Category Archives: Climatology

First images from new Landsat satellite capture northern Colorado Front Range

For four decades Landsat satellites have beamed back amazing pictures of the Earth from their perch far above the planet’s surface.  The latest craft in the series was launched last month and among the first images it captured were pictures of the area around Fort Collins and the Galena Fire burn scar.

The Landsat Data Continuity Mission took to space on February 11 to continue the joint program between NASA and the USGS.  This latest spacecraft has some of the highest resolution imagery devices of any Earth-observing satellite and will allow the agencies to monitor the natural and human processes taking place on the planet.

This week NASA released some of the first images from the new craft including its ‘Image of the Day’ from the Earth Observatory program on Thursday.  The photos capture the northern Colorado Front Range in natural color and one showing wavelengths of light not seen by the human eye.  The city of Fort Collins is clearly seen as is the Galena Fire burn scar west of Horsetooth Reservoir.

Below the images are further explanation from NASA.

landsat1.jpg
Made with reflected red, green, and blue light, the image from the Landsat Data Continuity Mission shows Fort Collins as the human eye would see it. (NASA)
landsat2.jpg
The image from the Landsat Data Continuity Mission shows the Fort Collins area in wavelengths of light not usually visible to people. Plants are green, city areas are purple, snow is pale blue, and bare earth is tan-pink. . (NASA)

From NASA:

On March 18, 2013, the newly launched Landsat Data Continuity Mission (LDCM) began to send back images of Earth from both of its instruments—the Operational Land Imager (OLI) and the Thermal Infrared Sensor (TIRS). This view of Fort Collins, Colorado, is among the satellite’s first images.

The images above are close-up views from the OLI sensor at its maximum resolution of 15 meters per pixel. The top image displays natural color, while the second image blends shortwave infrared, near-infrared, and green wavelengths (LDCM bands 7, 5, 3). The close-ups were cropped from larger Landsat scenes (downloadable beneath each web image) that show where the Great Plains meet the Front Range of the Rocky Mountains in Wyoming and Colorado.

“The first OLI and TIRS images look great right out of the box,” said Jim Irons, LDCM project scientist. “I have waited a long time to view the first LDCM images and I could not be more impressed with their appearance.”

Made with reflected red, green, and blue light, the top image shows Fort Collins as the human eye would see it. The city is a gray grid surrounded by the curving roads and brown yards of residential neighborhoods. White clouds cast black shadows on the ground below. Land freshly burned in the Galena fire is charcoal black—just slightly darker than the dark green coniferous forest to its west.

The second image shows Fort Collins in wavelengths of light not usually visible to people. Plants are green, city areas are purple, snow is pale blue, and bare earth is tan-pink. This combination of visible and infrared light reveals features of the landscape not otherwise visible. For example, irrigated parks, yards, and golf courses are bright green in this image, but brown in natural color. The Galena Fire burn scar is dark red and easy to distinguish from its surroundings.

The Landsat Data Continuity Mission was launched on February 11, 2013, to continue the four-decade-long Landsat record of Earth’s landscapes. LDCM represents an evolutionary advancement in technology from previous Landsat sensors, collecting more data daily and with greater fidelity. The imagers also include two new bands to improve the view of clouds and near-shore waters.

LDCM’s normal operations are scheduled to begin in late May 2013, after the instruments have been calibrated and the spacecraft has been fully checked out. At that time, NASA will hand over control of the satellite to the U.S. Geological Survey, and the satellite will be renamed Landsat 8.

Read more about LDCM and its imagery in the NASA story: A Closer Look at LDCM’s First Scene.

 

 

Image captures the start of spring as seen from space

Spring officially began this morning at 5:02am MDT.  It is during this time, the vernal equinox, that the Earth’s axis is not tilted toward or away from the Sun.  As a result equal amounts of the Sun’s light are directed to the Northern and Southern Hemispheres.

Soon after the event this morning one of NOAA’s GOES satellites captured the light on the face of the planet in near perfect equilibrium.

1309v1_20130320-Equinox.png
At 7:02 ET on March 20, 2013, Earth was at its equinox. At 7:45 ET, the GOES-13 satellite captured this full disk image of Earth. (NOAA) Click the image for a larger view.

From NOAA:

Mar 20, 2013
GOES Satellite Captures Spring Equinox
It is that time of year again (it happens twice) when the relative angle of Earth is perpendicular to the Sun, causing equal incoming solar energy to the Northern and Southern hemispheres – as well as equal day and nighttime. At 7:02 ET on March 20, 2013, Earth was at its equinox. At 7:45 ET, the GOES-13 satellite captured this full disk image of Earth. The visible imagery sensor on GOES requires sunlight to “see” clouds, and so it provides a useful example of the equinox. In this image the GOES imagery extends to each of the poles since the entire hemisphere is equally lit. After the equinox passes today, the Northern Hemisphere will be more lit than the Southern Hemisphere – causing the seasons. (Note: the Sun in this image is artificially created, though the GOES spacecraft does have sensors continually monitoring the Sun for solar activity.)

February 2013 Thornton weather recap: Colder, wetter than average month

Northeastern Colorado’s warm, dry winter took a bit of a turn during February as temperatures cooled and we finally received some much needed precipitation.

The month started out with a continuation of the warmer and drier conditions we saw in January.  Temperatures for the first days of the month were routinely near or above the 50 degree mark with little precipitation.

That changed on the 9th when low pressure moved through and served to cool things down to below normal.  No precipitation was seen however.

The following 10 days were relatively calm and tranquil but with varying temperatures.  The month’s high temperature was recorded on the 17th.

As we entered the last part of the month the weather turned much more unsettled and finally delivered a healthy dose of winter.  A weak system on the 19th and 20th brought light snow and was followed a few days later by a more significant system on the 24th.

The waning days of the month saw mostly below normal temperatures and one more day of light snow.

The average temperature in Thornton during February 2013 was 30.3 degrees.  Out at Denver International Airport, Denver officially had an average of 30.1 degrees.  Both were well below the historical February average of 32.5 degrees.

Temperatures in Thornton ranged from a high of 66.2 degrees on the 17th down to the lowest reading of 5.7 degrees on the 25th.  Only two days in Thornton failed to climb above freezing.

Denver saw its highest reading of 63 degrees on the 17th and lowest of 5 degrees on the 22nd with six days failing to climb above 32 degrees.  All 28 days of the month saw low temperatures below the freezing mark at both locations.

Precipitation was the real weather highlight of February 2013 given how dry the season had been up to then.  Thornton recorded 0.71 inches in its bucket while DIA saw 0.77 inches.  Average for February is 0.37 so both locations enjoyed above normal measurements.

In terms of snowfall, Thornton measured 11.9 inches of the white stuff.  Out at the airport they bested our area with 14.1 inches.  Historically February averages a mere 5.9 inches so both were well above normal.

Click here to view the ThorntonWeather.com February 2013 Climate Summary

feb-temps.jpg
Thornton, Colorado February 2013 Temperatures
feb-precip.jpg
Thornton, Colorado February 2013 Precipitation

From the National Weather Service:

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF FEBRUARY 2013...

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2013

WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR`S
                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
                                          NORMAL
................................................................
TEMPERATURE (F)
RECORD
 HIGH              77   02/28/2006
                        02/04/1890
 LOW              -25   02/01/1951
                        02/08/1936
HIGHEST            63   02/17        70      -7       65  02/25
LOWEST              5   02/22       -14      19        3  02/11
AVG. MAXIMUM     43.3              46.2    -2.9     38.7
AVG. MINIMUM     16.9              18.9    -2.0     18.1
MEAN             30.1              32.5    -2.4     28.4
DAYS MAX >= 90      0               0.0     0.0        0
DAYS MAX = .01         6               5.3     0.7        7
DAYS >= .10         4               0.7     3.3        2
DAYS >= .50         0               0.0     0.0        1
DAYS >= 1.00        0               0.0     0.0        0
GREATEST
 24 HR. TOTAL    0.43   02/24 TO 02/24           02/02 TO 02/03

SNOWFALL (INCHES)
RECORDS
 TOTAL           22.1   1912
TOTALS           14.1               5.7

DEGREE_DAYS
HEATING TOTAL     972               908      64     1055
 SINCE 7/1       4272              4439    -167     4380
COOLING TOTAL       0                 0       0        0
 SINCE 1/1          0                 0       0        0

FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05
....................................................

WIND (MPH)
AVERAGE WIND SPEED              10.3
RESULTANT WIND SPEED/DIRECTION   2/229
HIGHEST WIND SPEED/DIRECTION    35/360    DATE  02/15
HIGHEST GUST SPEED/DIRECTION    44/010    DATE  02/15

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.60
NUMBER OF DAYS FAIR            5
NUMBER OF DAYS PC             16
NUMBER OF DAYS CLOUDY          7

AVERAGE RH (PERCENT)     51

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       0
LIGHT RAIN                1     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                1     SNOW                       4
LIGHT SNOW               10     SLEET                      0
FOG                       9     FOG W/VIS

January 2013 Thornton weather recap: A colder and drier than average month

Looking back at January 2013 the numbers reveal a month that wasn’t particularly extraordinary by any measure.  Temperatures were slightly below average and precipitation was a bit less than normal.

The first half of the month was notable for cold while the second half for the most part was considerably warmer.

Temperatures for the first three days were well below normal before we entered a brief period with above average temperatures.  That was followed by very cold days on the 12th and 13th when high temperatures only reached the teens.  Most of the following two weeks were notable for highs in the 50s and 60s.

The month started out extraordinarily dry with a mere 0.3 inch of snow being recorded during the first 27 days.  On the 28th though we received a decent little shot of snow to drive up the numbers.

The average temperature for the month came in at 29.7 degrees.  This was a full degree below the Denver January average of 30.7 degrees.  At the official Denver station at Denver International Airport, the monthly average was slightly warmer at 30.3 degrees.

Temperatures in Thornton ranged from a high of 67.8 degrees on the 24th down to a low of -2.4 degrees on the 15th.  Denver recorded a highest temperature of 66 degrees, also on the 24th, and a low of -12 degrees on the 12th.

There were no temperature records set during the month.

In terms of precipitation, an anemic 0.21 inch was measured in Thornton while Denver fared better with 0.31 inch.  The January average is 0.41 inch so both locations were a good bit below normal.

Snowfall was similarly light with Thornton recording 3.7 inches, most of which fell during the storm on the 28th and 29th.  Out at DIA Denver officially measured 4.6 inches for the month.  Average for January is 7.0 inches.

None of the precipitation or snowfall measurements were records.

Click here to view Thornton’s January 2013 Climate Summary

2013-02-01_161619.jpg
Thornton, Colorado January 2013 Temperature Summary. (ThorntonWeather.com)
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Thornton, Colorado January 2013 Precipitation Summary. (ThorntonWeather.com)

From the National Weather Service:

...THE DENVER CLIMATE SUMMARY FOR THE MONTH OF JANUARY 2013...

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2013

WEATHER         OBSERVED          NORMAL DEPART LAST YEAR`S
                 VALUE   DATE(S) VALUE   FROM    VALUE DATE(S)
                                          NORMAL
................................................................
TEMPERATURE (F)
RECORD
 HIGH              76   01/27/1888
 LOW              -29   01/09/1875
HIGHEST            66   01/24        76     -10       66 01/21
LOWEST            -12   01/12       -29      17       -6 01/11
AVG. MAXIMUM     44.6              44.0     0.6     50.3
AVG. MINIMUM     16.0              17.4    -1.4     21.6
MEAN             30.3              30.7    -0.4     36.0
DAYS MAX >= 90      0               0.0     0.0        0
DAYS MAX = .01         4               4.1    -0.1        4
DAYS >= .10         1               0.9     0.1        1
DAYS >= .50         0               0.0     0.0        0
DAYS >= 1.00        0               0.0     0.0        0
GREATEST
 24 HR. TOTAL    0.22   01/28 TO 01/29

SNOWFALL (INCHES)
RECORDS
 TOTAL           24.3   1992
TOTALS            4.6               7.0

DEGREE_DAYS
HEATING TOTAL    1067              1063       4      891
 SINCE 7/1       3300              3531    -231     3325
COOLING TOTAL       0                 0       0        0
 SINCE 1/1          0                 0       0        0

FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05
..................................................

WIND (MPH)
AVERAGE WIND SPEED              8.8
RESULTANT WIND SPEED/DIRECTION   4/205
HIGHEST WIND SPEED/DIRECTION    38/290    DATE 01/24
HIGHEST GUST SPEED/DIRECTION    45/290    DATE 01/24

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR            8
NUMBER OF DAYS PC             20
NUMBER OF DAYS CLOUDY          3

AVERAGE RH (PERCENT)     48

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       0
LIGHT RAIN                1     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                1     SNOW                       1
LIGHT SNOW                5     SLEET                      0
FOG                       7     FOG W/VIS

Thornton’s February weather preview: Milder temps, dry conditions typical during month

Denver Climatological Preview - February 2013As we wrap up a January that was pretty much average in terms of temperature and precipitation, we look to February with hope for relief from the dry conditions we have seen thus far this winter.  Unfortunately historically February is a relatively dry month but we do start working off winter as temperatures climb.

To date Denver’s seasonal snowfall is 10.8 inches below average and Thornton is even further behind.  February though is only the Mile High City’s sixth snowiest month so while we can receive big storms in February, we can’t count on making up much ground.

For those looking forward to milder weather, average temperatures do increase during the month as a sign that winter is fading and spring is approaching.

For the complete February preview including a look at historical averages and extremes as well as a look at what long range forecasts are predicting, click here. 

North-central Colorado snowpack at second lowest level to date in 34 years

The 2012 / 2013 snow season has been dismal and while December brought some hope for recovery, recent weeks have seen snowpack decline once again.  For the drought and fire weary state of Colorado the data does not bode well.

For the north-central Colorado mountains, the January 22 snowpack is at its second lowest level to date since 1979.  Only 1981 saw worse results this far into the season.

According to the latest Colorado SNOTEL reports, the South Platte, North Platte and Upper Colorado River basins are at 57%, 65% and 60% of normal respectively.  Statewide Colorado snowpack is a dismal 62% of average.

Is there hope?  Mother Nature certainly works on her own schedule so it is possible we could see a recovery.  However the latest 3-month outlook from the Climate Prediction Center forecasts warmer and drier than normal temperatures.

North-central Colorado snowpack through January 22. (NRCS)
North-central Colorado snowpack through January 22. Click the image for a larger view. (NRCS)

December 2012 Thornton weather recap: Warmer, drier than normal again

In the immediate days following the end of the month most of us are likely to remember the bitter cold that closed it out.  However an unseasonably mild start to December 2012 made the month not only finish warmer than average but also drier than normal.

December started out very mild with the first eight days seeing overall average temperatures 12.7 degrees above normal.  Colder air moved in after that for a few days before above normal temperatures returned again and continued through the 18th.

Another three day cold spell arrived but mild temperatures returned on the 21st.  Christmas Eve ushered in a big chill that lingered through the end of the month.

Overall December’s average temperature in Denver as measured at Denver International Airport was 31.2 degrees.  This was 1.2 degrees above the 1981 to 2000 average of 31.0 degrees.  Here in Thornton we were closer to average with a monthly average temperature of 30.5 degrees.

Denver temperatures ranged from a high of 69 degrees on the 5th down to a bitter cold low of -2 on the 26th.  Eight days failed to reach high temperatures above the freezing mark in the Mile High City and it recorded two days with low temperatures at or below zero.

Thornton saw its warmest temperature on the 1st of the month with a high of 67.6 degrees and its coldest temperature of 00.4 degrees on the 26th.  Like Denver, Thornton recorded eight days with high temperatures failing to reach 32 degrees.

Precipitation as recorded at DIA was slightly below normal during December.  0.27 inch was recorded as compared to the average of 0.35 inch.  Thornton was unfortunately drier as we only recorded 0.19 inch of precipitation.

Snowfall fell short of average as well during the month.  Denver recorded 5.2 inches and Thornton 3.7 inches.  On average the Mile High City records 8.4 inches during the month.

With the end of the month, Denver’s 2012 – 2013 seasonal snowfall total falls further behind average.  To date it is 8.8 inches below normal.  While the snowpack has rebounded considerably thanks to the storms in the latter half of the month, it is currently at 72% of normal.

Click here to view Thornton’s December 2012 Climate Summary.

Thornton, Colorado December 2012 Temperature Summary. (ThorntonWeather.com)
Thornton, Colorado December 2012 Temperature Summary. (ThorntonWeather.com)
Thornton, Colorado December 2012 Precipitation Summary. (ThorntonWeather.com)
Thornton, Colorado December 2012 Precipitation Summary. (ThorntonWeather.com)

From the National Weather Service:

...THE DENVER CO CLIMATE SUMMARY FOR THE MONTH OF DECEMBER 2012... 

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2012

WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR`S
                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
                                          NORMAL
................................................................ 
TEMPERATURE (F)
RECORD
 HIGH              79   12/05/1939
 LOW              -25   12/22/1990
                        12/24/1876
HIGHEST            69   12/05        65      -4       58  12/18
LOWEST             -2   12/26       -10       8       -5  12/06
AVG. MAXIMUM     44.2              42.8     1.4     38.5
AVG. MINIMUM     18.3              17.1     1.2     14.8
MEAN             31.2              30.0     1.2     26.6
DAYS MAX >= 90      0               0.0     0.0        0
DAYS MAX = .01         5               4.1     0.9        6
DAYS >= .10         1               1.1    -0.1        3
DAYS >= .50         0               0.1    -0.1        0
DAYS >= 1.00        0               0.0     0.0        0
GREATEST
 24 HR. TOTAL    0.20   12/24 TO 12/25

SNOWFALL (INCHES)
RECORDS
 TOTAL           57.4   1913
TOTALS            5.2               8.4

DEGREE_DAYS
HEATING TOTAL    1038              1086     -48     1182
 SINCE 7/1       2233              2468    -235     2434
COOLING TOTAL       0                 0       0        0
 SINCE 1/1       1236               769     467      964

FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05
................................................... 

WIND (MPH)
AVERAGE WIND SPEED              9.9
RESULTANT WIND SPEED/DIRECTION   3/215
HIGHEST WIND SPEED/DIRECTION    38/270    DATE  12/03
HIGHEST GUST SPEED/DIRECTION    48/290    DATE  12/03

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.60
NUMBER OF DAYS FAIR            1
NUMBER OF DAYS PC             22
NUMBER OF DAYS CLOUDY          8

AVERAGE RH (PERCENT)     49

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     MIXED PRECIP               0
HEAVY RAIN                0     RAIN                       0
LIGHT RAIN                0     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       2
LIGHT SNOW                8     SLEET                      0
FOG                      10     FOG W/VIS

Thornton’s January weather preview: Typically a cold, but not snowy month

Denver's January weather and climatology preview for 2013.As we begin the new year the winter chill begins to set in.  While January can see its share of extremes, the month historically sees stable temperatures and is usually relatively dry.

January ranks as the second coldest month in Denver next to December with average temperatures remaining virtually the same from the start to the end of the month.  In terms of snowfall, the month only ranks as the fourth snowiest and it is not uncommon for it to be quite dry.

What does January 2013 hold for us?  Indications are that we may very well continue the recent pattern of below normal temperatures and relatively dry conditions.

For the complete January preview including a look at historical averages and extremes, click here. 

2012 Thornton weather recap: Warm and dry conditions dominated

Thornton, Colorado 2012 weather recapAs the sun sets on 2012 and the new year dawns, we look back on the past 12 months and can see it for what it was: unusually dry and warm.  While we were spared monster blizzards or much severe weather, there were still noteworthy weather events.

In terms of temperatures, Denver recorded an overall average of 53.8 degrees as recorded at Denver International Airport.  This was 3.4 degrees above average and put 2012 in the history books as the third warmest year in Denver history.  Here in Thornton we were, as usual, a bit cooler with an annual average temperature of 52.9 degrees.

The National Weather Service reported 73 days with temperatures at or above 90 degrees which far exceeds the average of 40 such days we normally see annually.  Here in Thornton we too saw more than average with 62 days of 90 degree or hotter temperatures.

The late spring and early summer proved to be record setting in terms of heat.  The month of June set a record high temperature average and July was the hottest month in Denver history.  Two days, June 25th and 26th broke daily high temperature records and tied Denver’s all-time high temperature of 105 degrees.

On the opposite end of the thermometer, Denver officially recorded 132 days with temperatures at or below freezing.  Here in Thornton we recorded two more with 134 days.  On average the Mile High City records 157 days of freezing temperatures.

While the year was unusually warm, it was also extraordinarily dry.  A mere 10.11 inches of precipitation was recorded in Denver’s rain bucket at DIA, 4.19 inches below normal.  Here in Thornton we were even drier as we recorded 9.61 inches of precipitation in 2012.  While extremely dry, neither measurement was low enough to make the list of top 15 driest years.

Total snowfall for the calendar year ended up at 38.5 inches at DIA and 35.1 inches in Thornton. Both locations fell well short of the Denver annual average snowfall of 53.5 inches.  Denver’s snowfall was enough to keep it off the list of top 15 least snowiest years.  However Thornton’s measurement would have made it the 13th least snowiest on Denver’s list.

Snowfall started out reasonably strong thanks to a healthy snowfall total in February.  However while March is on average our snowiest month, that did not hold true in 2012.  A mere 0.03 inch of precipitation was recorded setting the stage for the balance of a dry year.

Combined, June, July and August recorded only 1.81 inches of precipitation at DIA.  This was an astonishing 4.02 inches below average for that period.  Thornton fared only slightly better over the period with 2.34 inches.

While September brought above normal precipitation, the final three months of 2012 returned us to drier than normal conditions.

Extreme weather events were not particularly common in 2012.  There was a distinct lack of heavy snow events and even spring’s severe weather season was relatively tame.

However, the hot summer temperatures and tinder dry conditions did lead to a deadly and destructive wildfire season.

The High Park Fire in June quickly became the second largest wildfire in Colorado history.  That blaze was soon followed by the Waldo Canyon Fire west of Colorado Springs which went into the history books as the most destructive blaze in state history.

Click here for Thornton’s 2012 Climate Summary Report

Thornton, Colorado 2012 Temperature Summary (ThorntonWeather.com)
Thornton, Colorado 2012 Temperature Summary (ThorntonWeather.com)
Thornton, Colorado 2012 Precipitation Summary (ThorntonWeather.com)
Thornton, Colorado 2012 Precipitation Summary (ThorntonWeather.com)
Denver, Colorado 2012 Temperature and Precipitation Summary (National Weather Service)
Denver, Colorado 2012 Temperature and Precipitation Summary (National Weather Service)

From the National Weather Service:

CLIMATE REPORT
NATIONAL WEATHER SERVICE BOULDER, CO
130 AM MST TUE JAN 1 2013

...THE DENVER CO CLIMATE SUMMARY FOR THE YEAR OF 2012...

CLIMATE NORMAL PERIOD 1981 TO 2010
CLIMATE RECORD PERIOD 1872 TO 2012

WEATHER         OBSERVED          NORMAL  DEPART  LAST YEAR`S
                 VALUE   DATE(S)  VALUE   FROM    VALUE  DATE(S)
                                          NORMAL
................................................................ 
TEMPERATURE (F)
RECORD
 HIGH             105   06/26/2012
                        06/25/2012
                        07/20/2005
 LOW              -29   01/09/1875
HIGHEST           105R  06/26        64      41       99  08/25
                        06/25                             07/31
                                                          07/04
LOWEST             -6   01/11        36     -42      -17  02/02
AVG. MAXIMUM     68.4              64.7     3.7     64.8
AVG. MINIMUM     39.3              36.3     3.0     36.4
MEAN             53.9              50.5     3.4     50.6
DAYS MAX >= 90     73              39.6    33.4       50
DAYS MAX <= 32     19              20.0    -1.0       23
DAYS MIN <= 32    132             156.9   -24.9      158
DAYS MIN <= 0       4               5.8    -1.8       12

PRECIPITATION (INCHES)
RECORD
 MAXIMUM        23.31   1196
 MINIMUM         7.29   2008
TOTALS          10.11             14.30   -4.19    17.31
DAILY AVG.       0.03              0.04   -0.01     0.05
DAYS >= .01        52              79.7   -27.7       80
DAYS >= .10        23              34.9   -11.9       37
DAYS >= .50         9               7.6     1.4       10
DAYS >= 1.00        1               2.3    -1.3        6
GREATEST
 24 HR. TOTAL    1.63   MM                       05/11 TO 05/12
                                                          10/26 TO 10/26
                                                          10/26 TO 10/26
 STORM TOTAL       MM                               2.52
 (MM/DD(HH))            MM                    05/12(00) TO 05/12(00)
                                                 10/26(00) TO 10/26(00)6
                                                 10/26(00) TO 10/26(00)6

SNOWFALL (INCHES)
RECORDS
 TOTAL             MM   5
 24 HR TOTAL       MM
 SNOW DEPTH        MM   MM
TOTALS           38.5              53.8   -15.3     46.8
 LIQUID EQUIV    3.85              5.40   -1.55     4.68
SINCE 7/1        12.4              22.5   -10.1     29.5
 LIQUID 7/1      1.24              2.20   -0.96     2.95
SNOWDEPTH AVG.      0                MM      MM        0
DAYS >= TRACE      36              33.3     2.7       41
DAYS >= 1.0        13              16.3    -3.3       16
GREATEST
 SNOW DEPTH        11   02/04                          7  01/10
                                                          01/11
 24 HR TOTAL     12.5   MM                       10/26 TO 10/26
                                                          10/26 TO 10/26
                                                          10/26 TO 10/26
 STORM TOTAL       MM                                8.5
 (MM/DD(HH))            MM                    10/26(00) TO 10/26(00)
                                                 10/26(00) TO 10/26(00)6
                                                 10/26(00) TO 10/26(00)6

DEGREE_DAYS
HEATING TOTAL    5198              6059    -861     6069
 SINCE 7/1         MM              2468      MM       MM
COOLING TOTAL    1236                 0    1236      964
 SINCE 1/1       1236               769     467      964

FREEZE DATES
RECORD
 EARLIEST     09/08/1962
 LATEST       06/08/2007
EARLIEST                        10/07
LATEST                          05/05
....................................................... 

WIND (MPH)
AVERAGE WIND SPEED              10.3
RESULTANT WIND SPEED/DIRECTION   3/205
HIGHEST WIND SPEED/DIRECTION    52/240    DATE  06/02
HIGHEST GUST SPEED/DIRECTION    67/250    DATE  06/02

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM
AVERAGE SKY COVER           0.50
NUMBER OF DAYS FAIR           86
NUMBER OF DAYS PC            235
NUMBER OF DAYS CLOUDY         45

AVERAGE RH (PERCENT)     44

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              0     MIXED PRECIP               0
HEAVY RAIN                4     RAIN                      12
LIGHT RAIN               45     FREEZING RAIN              0
LT FREEZING RAIN          1     HAIL                       3
HEAVY SNOW                4     SNOW                      15
LIGHT SNOW               37     SLEET                      0
FOG                      73     FOG W/VIS <= 1/4 MILE     21
HAZE                     51

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.

Denver’s white Christmas history: Snow on the holiday not as common as you might think

For many the holiday season isn’t complete without a chill in the air and snow on the ground. Here in Denver we historically enjoy a better chance of experiencing the proverbial white Christmas than many places in the nation.

How the Mile High City fares in experiencing a white Christmas does depend on your definition of one. If it means having actual snowfall on Christmas Day the chances aren’t that good. However if simply having snow on the ground suffices, the chances improve considerably.

For a complete look at Denver’s Christmas weather statistics, click here.

For the latest Thornton weather forecast for Christmas, check out our forecast page.

Historical probability of a white Christmas (at least 1" of snow on the ground).  NOAA / NCDC
Historical probability of a white Christmas (at least 1" of snow on the ground). NOAA / NCDC