November was an unseasonably warm and unusually dry month. As we look into December, that trend looks to change, particularly when it comes to temperatures.
The month brings with it the official start to winter and the month usually brings with it our first real taste of Arctic temperatures. Precipitation can be hit or miss with monster snowstorms possible but we have also seen starkly dry years.
Current long range forecasts indicate that for at least the first half of the month we will see unusually cold temperatures and have the potential for better than average levels of precipitation.
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.
Thornton, Colorado December 2012 Temperature 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
December 30 to January 5: This Week in Denver Weather History
Cold, snow and wind are the dominant historical weather events for our look back at this week in Denver weather history.
From the National Weather Service:
25-31
In 1980…temperatures were unusually warm during the week between Christmas and New Year’s. High temperatures for the week ranged from the mid-50’s to the mid-70’s. Four temperature records were set. Record highs occurred on the 26th with 68 degrees…the 27th with 75 degrees…and the 30th with 71 degrees. A record high minimum temperature of 41 degrees occurred on the 27th.
29-30
In 1898…heavy snowfall totaled 6.2 inches in downtown Denver. Northeast winds were sustained to 35 mph with gusts to 40 mph on the 29th.
In 1912…strong winds buffeted Boulder…causing hundreds of dollars damage. The winds were described as one of the most terrific in the history of the city.
In 1923…a cold wave caused temperatures to plunge 58 degrees in 24 hours. The temperature was 54 degrees at 2:00 pm on the 29th and only 4 degrees below zero at the same time on the 30th. The low temperature of 14 degrees on the 29th was the high temperature on the 30th. The low temperature on the 30th dipped to 10 degrees below zero. Light snowfall totaled only 0.7 inch. Northeast winds were sustained to 23 mph on the 29th.
In 2008…very strong Chinook winds blasted areas in and near the foothills of Boulder and Jefferson counties. The wind blew down trees and power poles…downed electrical lines and fences…and damaged homes and vehicles. Scattered power outages were reported along the Front Range. In metropolitan Denver alone…24000 Xcel customers were affected by the outages. Four planed were damaged at the Vance Brand Municipal Airport in Longmont…one was heavily damaged. Insurance companies estimated up to 7 million dollars in damage. Peak wind gusts included 87 mph at the national wind technology center…86 mph…2 miles north of Longmont; 77 mph at Erie…and 75 mph at Lafayette. On the 30th…a peak wind gust to 47 mph was recorded at Denver International Airport. .
30
In 1875…snow fell from the early morning into the early evening. While the amount of snowfall was not recorded… Precipitation from melted snow totaled 0.53 inch. Good sleighing was reported…so snowfall must have been 5 inches or more.
In 1895…northwest winds were sustained to 60 mph in the city.
In 1897…west winds sustained to 52 mph with gusts to 60 mph warmed the temperature to a high of 55 degrees.
In 1912…west winds were sustained to 48 mph with gusts to 52 mph. The Chinook winds warmed the temperature to a high of 50 degrees.
In 1928…snowfall was 0.1 inch in downtown Denver. This was the only measurable snow of the month…ranking the month the third least snowiest on record in the city.
In 1990…strong downslope winds buffeted the eastern foothills. Wind gusts to 91 mph were recorded atop Table Mesa in southwest Boulder…while a gust to 94 mph was clocked at Rollinsville. The high winds caused whiteout conditions due to blowing snow along some highways south and north of Boulder. The high winds downed power lines near the Rocky Flats plant south of Boulder.
In 1998…high winds continued to buffet areas in and near the foothills. Near Evergreen…a 100-foot-high blue spruce crashed down on the roof of a home…splitting the corrugated metal roof in half. Fortunately…the tree… Which measured 10 feet in circumference…only penetrated the home’s interior in a few places. Peak wind reports included: 90 mph at Wondervu…88 mph at the Rocky Flats test facility…83 mph near Conifer…and 82 mph atop Blue Mountain near Coal Creek Canyon. West winds gusted to 39 mph at Denver International Airport.
December 23 to December 29: This Week in Denver Weather History
Christmas week has seen many notable weather events which are forever emblazoned on Coloradans’ memories. The holidays of course seem to heighten these memories but the events themselves are no less significant. There was of course the infamous Christmas Eve Blizzard of 1982 and more recently in 2006, a storm hit just after the holiday that buried us in a blanket of white.
From the National Weather Service:
17-24
In 1924…a prolonged cold spell occurred after mild temperatures during the first half of the month. Most low temperatures dipped below zero with the coldest reading of 15 degrees below zero occurring on the 24th. The high temperature of only 5 degrees on the 18th was a record low maximum for the date.
18-24
In 1998…a vigorous cold front with north winds gusting as high as 38 mph at Denver International Airport on the 18th dropped temperatures from a high of 51 degrees to a low of just 6 degrees before midnight. The arctic air mass that settled over metro Denver produced intermittent light snow and a week-long protracted cold spell that caused low temperatures to plunge well below zero for 6 consecutive nights. The coldest temperature was 19 degrees below zero on the morning of the 22nd. High temperatures climbed only into the single digits on 4 consecutive days…from the 19th through the 22nd. At least 15 people…mostly homeless… Were treated for hypothermia at area hospitals. The bitter cold weather was responsible…either directly or indirectly… For at least 5 fatalities. Three of the victims died directly from exposure. The cold weather also caused intermittent power outages. Following the cold snap… Thawing water pipes cracked and burst in several homes and businesses…causing extensive damage. Only one temperature record was set. The high temperature of only 7 degrees on the 19th set a record low maximum for the date.
19-23
In 1990…a surge of very cold arctic air invaded metro Denver. Many temperature records were broken as the mercury remained at or below zero for 85.5 hours at Stapleton International Airport…making it the third longest period of subzero readings in 118 years of record keeping. On the morning of the 22nd…the mercury plunged to 25 degrees below zero…which equaled the all-time record low temperature for the month set on December 24…1876. In the foothills southwest of Denver at tiny town…the mercury plunged to 33 degrees below zero on the morning of the 21st. On the same morning at Castle Rock the temperature dipped to 26 degrees below zero. During the period…other daily temperature records were set at Denver…including: record low maximum of 3 degrees below zero on the 20th and a record low of 17 degrees below zero on the 23rd. The record low was equaled with 16 degrees below zero on the 20th and 21 degrees below zero on the 21st. Snowfall totaled 2.7 inches at Stapleton International Airport from the 19th through the 21st.
20-23
In 1918…light snowfall on each day totaled 12.0 inches over downtown Denver. Northeast winds were sustained to 16 mph on the 21st.
20-25
In 1983…an extremely bitter cold spell occurred. The temperature remained below zero for 115 hours in Denver… The longest sub-zero period on record. The mercury dipped to 21 degrees below zero on the 21st…the coldest recorded temperature in over 20 years. The cold was accompanied by winds that plunged chill factors to 50 to 70 degrees below zero. Two people froze to death in Denver; both were found outside dead of exposure. Numerous cases of frostbite were reported. Hundreds of water pipes broke from the intense cold…water mains and natural gas lines also fractured…and electricity consumption reached record levels. Light snow totaling 5.8 inches fell at times…and holiday traffic was delayed at Stapleton International Airport for several hours. Eight daily temperature records were set at the time. The all-time record low maximum temperature for the month of 8 degrees below zero on the 21st still stands today. Other temperature records still standing include record low maximum temperatures of 5 degrees below zero on both the 22nd and 23rd and 4 degrees below zero on the 24th.
21-23
In 1924…heavy snowfall totaled 7.9 inches over downtown Denver. During the storm north to northeast winds were sustained to 21 mph. Temperatures were quite cold…ranging from a high of 24 degrees on the 21st to a low of 5 degrees below zero on the 23rd.
In 1964…high winds were recorded along the eastern foothills. A wind gust to 100 mph was registered at Jefferson County Airport near Broomfield. In Boulder… Where many thousands of dollars in damage occurred…warm Chinook winds gusted in excess of 45 mph downtown. A wind gust to 82 mph was recorded at the National Center for Atmospheric Research in Boulder. Heavy damage to power lines…homes…and roads was reported at Evergreen…Golden… And Boulder. Several people were injured by wind-caused accidents. West winds gusted to 53 mph on the 22nd and to 51 mph on the 23rd at Stapleton International Airport where some blowing dust occurred. The Chinook winds warmed temperatures in Denver to highs of 68 degrees on the 22nd and 71 degrees on the 23rd.
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.
The wintry weather that moved through Colorado over the past 48 hours provided some relief to the drought-stricken state. NASA satellites captured the snowy landscape of the Centennial State as the storm moved off toward the Midwest.
The system covered much of the higher elevations of the Rocky Mountain region in snowfall. For Colorado this brought snow to the high country much to the delight of ski resorts and skiers.
In Denver the storm brought very cold temperatures but not as much snow as was hoped. Officially the Mile High City recorded 1.7 inches bringing the seasonal total to 9.8 inches, well below normal.
The image from NASA’s Aqua satellite was taken on Wednesday, December 19 as the storm began to move out onto the plains. The snow covered mountains west of Denver are clearly seen while cloud covers the lower elevations.
Satellite imagery shows the pre-Christmas snowstorm that blanketed Colorado. Click the image for a larger view. (NASA)
December 16 to December 22: This Week in Denver Weather History
Many notable high wind and heavy snow events appear on our look back at this week in Denver weather history. Perhaps the one most residents will remember is the 2006 pre-Christmas blizzard which buried Denver under a blanket of white that lasted until February.
From the National Weather Service:
15-16
In 1964…high winds raked metro Denver…causing considerable damage. Wind gusts to 81 mph were recorded at Rocky Flats northwest of Denver…94 mph at Jefferson County Airport near Broomfield…48 mph in downtown Boulder…and 70 mph in Littleton. West wind gusts to 67 mph were recorded at Stapleton International Airport. A man working on construction in downtown Denver died from injuries after being struck by a 5-foot by 8-foot section of plank runway blown by the strong winds. Several people were blown down by the strong winds or hit by flying objects. Buildings… Roads…trees…and power equipment were damaged. Roads were closed east of Denver due to blowing dust.
In 1981…wind gusts to 60 mph were common in the foothills northwest of Denver. West wind gusts to 47 mph were recorded at Stapleton International Airport where the visibility was briefly reduced to 3 miles in blowing dust.
In 1996…strong pre-frontal winds developed in the foothills of Boulder County ahead of an arctic cold front that moved into northeastern Colorado late on the morning of the 16th. Wind gusts of 70 to 75 mph were clocked at Table Mesa in southwest Boulder.
16
In 1912…northwest winds were sustained to 44 mph with an extreme velocity of 45 mph.
In 1921…north winds were sustained to 46 mph with gusts to 50 mph behind a vigorous cold front. Only a trace of snow fell.
In 1954…a vigorous cold front produced sustained north winds to 45 mph with gusts as high 54 mph. Visibility was reduced to 1 mile in blowing dust at Stapleton Airport.
In 1955…sustained west winds to 44 mph with gusts as high as 58 mph were recorded at Stapleton Airport.
In 1994…a wind gust to 108 mph was recorded atop Squaw Mountain west of Denver with a gust to 92 mph in Rollinsville southwest of Boulder. West winds gusted to 48 mph at Stapleton International Airport.
In 1996…a vigorous arctic cold front moved across metro Denver. Heavy snow and strong winds accompanied the front as near whiteout conditions in snow and blowing snow developed suddenly. Northerly winds gusted from 40 to 60 mph behind the front. Dozens of accidents occurred as roads and highways quickly turned to a glaze of ice. Snowfall amounts ranged from 4 to 6 inches across metro Denver and in the foothills. The exception was at Eldorado Springs south of Boulder where 8 inches of new snow were measured. Snowfall totaled only 1.8 inches at the site of the former Stapleton International Airport. Officially…this was the only measurable snow of the month in Denver. At Denver International Airport…north winds gusted to 34 mph.
In 1999…another brief round of high winds developed in and near the foothills of Boulder County. Peak wind gusts included 83 mph at the National Center for Atmospheric Research near Boulder and 74 mph atop Niwot Ridge and at the national wind technology center on Rocky Flats south of Boulder. West winds gusted to only 33 mph at Denver International Airport where the temperature warmed to a high of 54 degrees.
In 2000…high winds in the mountains spread into the foothills west of Denver. Winds gusted to 87 mph at Georgetown Lake and at the National Center for Atmospheric Research in Boulder. Winds gusted to 72 mph at the national wind technology center south of Boulder.
16-17
In 1908…heavy snowfall totaled 7.9 inches in downtown Denver where north winds were sustained to 20 mph on the 17th. Temperatures were in the teens and 20’s.
In 1939…low temperatures of 49 degrees on the 16th and 43 degrees on the 17th were record high minimums for the dates. High temperatures of 65 on the 16th and 72 on the 17th were not records.
In 1980…Chinook winds blew through the night in Boulder with a peak reported gust to 75 mph. Northwest winds gusted to 30 mph at Stapleton International Airport on the 17th. The strong Chinook winds warmed temperatures to record daily highs of 70 degrees on the 16th and 73 degrees on the 17th.
17
In 2000…high winds gusting from 60 to 74 mph howled across the northeast plains of Colorado. In Parker where winds gusted to 60 mph…a 20-foot by 40-foot piece of roof was ripped from a building. West winds gusted to 53 mph at Denver International Airport. This was the highest wind gust of the month at the airport. An intense…but very localized wind gust to 112 mph was measured near Georgetown lake in the foothills west of Denver.
December 9 to December 15: This Week in Denver Weather History
Heavy snow and damaging wind are at the forefront of our look back at this week in Denver weather history.
From the National Weather Service:
2-17
In 1939…more than 2 weeks of unseasonably warm weather made the month the 3rd warmest on record. Seven daily temperature records were set…including the all-time record high temperature for the month of 79 degrees on the 5th. Daytime highs were balmy with 14 days in the 60’s and 70’s. Low temperatures dipped to freezing or below on only 5 days. The period was dry with only a trace of snow on the 12th.
3-15
In 1972…a protracted cold spell held an icy grip on metro Denver when maximum temperatures never reached above freezing for 10 consecutive days from the 3rd through the 12th and minimum temperatures dipped below zero on eleven consecutive days from the 5th through the 15th. Daily low temperature records were set with 15 degrees below zero on the 5th…17 degrees below zero on the 6th… And 18 degrees below zero on the 10th. Daily record low maximum readings were set with 3 degrees on the 6th and 6 degrees on the 9th. The very cold temperatures were caused by 3 to 5 inches of snow cover and a Canadian air mass.
7-9
In 1919…an apparent arctic cold front brought extreme cold and light snow to the city. Snowfall totaled only 2.5 inches on the 7th and 8th. Temperatures dipped to lows of 14 degrees below zero on the 8th and to 20 degrees below zero on the 9th. Both readings were daily record minimums. High temperatures were only 4 degrees on the 8th and 7 degrees on the 9th.
In 1923…a major storm dumped 13.5 inches of snowfall on downtown Denver. The apparent post-frontal snowfall started during the late afternoon of the 7th and continued through the evening of the 9th. Temperatures dipped from a high of 66 degrees on the 7th with west winds sustained to 35 mph to a low of only 14 degrees on the 9th…with north winds sustained to 25 mph.
8-9
In 1943…4.5 inches of snow fell in downtown Denver. This was the only measurable snow of the month. North winds were sustained to 26 mph on the 8th.
In 2003…snowfall totaled 3 to 6 inches across metro Denver. Snowfall was heavier in and near the foothills with 8.0 inches measured in Boulder and 10 miles southwest of Sedalia. Snowfall was 3.9 inches at the site of the former Stapleton International Airport. Most of the snow fell on the 8th…as the snow ended shortly after midnight. North winds gusted to 29 mph at Denver International Airport.
In 2008…an upslope snowstorm produced heavy snow in and near the foothills of Boulder…Jefferson and Douglas counties… And along the palmer divide south of Denver. Storm totals in the foothills ranged from 8 to 15 inches. In Boulder and in areas west and south of Denver…storm totals ranged from 6 to 13 inches. The snowfall measurement at Denver International Airport was 3.9 inches.
December 2 to December 8: This Week in Denver Weather History
This week has historically been an extremely eventful one in Denver with many notable weather events, most of which are snow or wind related. The most significant event occurred 99 years ago when the city received its biggest snowstorm on record – an astonishing 45.7 inches. Details on that event and many others are below.
From the National Weather Service:
30-2
In 1975…very strong Chinook winds up to 100 mph caused damage to homes…aircraft…aircraft hangars…mobile homes… Cars…and power lines along the eastern foothills. Strong northwest winds gusted to 39 mph at Stapleton International Airport on both the 30th and the 1st.
1-2
In 1933…apparent post-frontal heavy snowfall totaled 8.0 inches across downtown Denver. North winds were sustained to 17 mph with an extreme velocity to 18 mph on the 1st.
In 1981 strong winds gusted to over 70 mph along the foothills. A peak gust to 100 mph was recorded at Wondervu. A gust to 94 mph was recorded just west of Boulder. Roofs on houses were damaged in the Evergreen area…and some mobile homes also were damaged. At Stapleton International Airport…northwest winds gusted 44 mph on the 1st and 37 mph on the 2nd.
1-5
In 1913…the 1st marked the start of the heaviest 5-day total snowfall in the city’s history. During this period snowfall totaled 45.7 inches. Starting on the 1st…snow fell intermittently for 3 days and accumulated a little over 8 inches. On the 4th and 5th…an additional 37.4 inches of snow fell. At Georgetown in the foothills west of Denver even more snow fell…86 inches over the 5 days with the most…63 inches…on the 4th. In Colorado…snowfall was heavy along the eastern slopes of the mountains from the palmer divide north. High winds during the storm caused heavy drifting…which blocked all transportation. Snow cover of an inch or more from the storm persisted for 60 consecutive days from the 1st through January 29…1914. Additional snowfall in December and January prolonged the number of days. This is the third longest period of snow cover on record in the city.
2
In 1893…northwest winds were sustained to 42 mph with gusts to 46 mph. Snowfall was only 1.4 inches in the city.
In 1895…0.01 inch of melted snow from 0.7 inch of snowfall was the only measurable precipitation of the month in downtown Denver…ranking the month the 3rd driest December on record.
In 1899…post-frontal northeast winds sustained to 44 mph with gusts to 59 mph caused the temperature to plunge from a high of 55 degrees to a low of 15 degrees. Snowfall was only 1.0 inch.
In 1902…apparent post-frontal northwest winds were sustained to 45 mph with gusts to 53 mph. A trace of snow fell.
In 1905…only a trace of snow fell in downtown Denver. This was the only snow and precipitation for the month… Ranking the month the second driest and the second least snowiest December on record.
In 1921…snowfall was 5.5 inches in downtown Denver. Northwest winds were sustained to 24 mph with an extreme velocity of 25 mph.
In 1951…a vigorous pacific cold front produced a northwest wind gust to 51 mph at Stapleton Airport where brief blowing dust was observed.
In 1957…a strong pacific cold front produced northwest wind gusts to 54 mph at Stapleton Airport where the surface visibility was briefly reduced to 1 1/2 miles in blowing dust.
In 1977…high winds in Boulder lifted a warehouse from its foundation and ripped it apart. Wind gusts from 60 to 103 mph toppled and injured a man while walking. Winds were clocked to 104 mph at Nederland…100 mph at Morrison…and 62 mph at Rocky Flats. Northwest winds gusted to 41 mph at Stapleton International Airport.
In 1996…for the second day in a row high winds ripped the Front Range foothills. Winds gusted to 81 mph in Golden Gate Canyon. West-northwest winds gusted to 37 mph at Denver International Airport.
Thus far the snow season has been far less than kind to Colorado. Snow totals are running well below normal from the plains to the Rockies.
December may bring some hope as the month is our third snowiest. The month brings with it the official start to winter and the month usually brings with it our first real taste of Arctic temperatures.
Precipitation can be hit or miss with monster snowstorms possible but we have also seen starkly dry years.
Current long range forecasts indicate we may very well see continued dry and warm weather.
November was an unseasonably warm and unusually dry month. As we look into December, that trend looks to change, particularly when it comes to temperatures.
