Preliminary
Wyoming Monthly Climatology
December 2003

Statewide Summary

Temperatures for the month of December were well above normal over most of the northern half of Wyoming. Average temperatures ranged from >8 degrees above normal over portions of Teton County to near normal over portions of Carbon County. Precipitation for the month of December was quite variable across the state. The heaviest moisture >200 percent of normal occurred over the western portions of the state while amounts <5 percent of normal occurred over parts most of Campbell County. The mountain snow pack has improved in December across the state and is about average for the beginning of January. This improvement was helped by the snow storms of 12-14 December, 25-27 December, and 28-30 December. Soil moisture on 1 January 2004 showed all but the extreme NE corner of Wyoming as normal. At Torrington in eastern Wyoming, soil moisture, remained essentially unchanged, although some variation occurred near the surface. The drought over Wyoming has remained essentially unchanged during December. In 2003, average temperatures ranged between -0.5°F and +4.0°F for normal and precipitation ranged from <70% over Sweetwater County to >120 percent over portions of Hot Springs and Park Counties.

Cheyenne

The average temperature in December was 30.0°F. This is 2.9°F above normal for the month. The maximum temperature for the month was 57°F on the 6th and the minimum of 5°F occurred just a day earlier on the 5th. Precipitation total of 0.84 inch is 183 percent of normal. Snowfall totaled 9.7 inches and is 154 percent of the long term mean. For 2004, the average temperature was 48.8°F or 3.8°F above normal. Precipitation totaled 11.27 inches or 72.9 percent of normal. Snowfall totaled 65.3 inches or 108 percent of normal.

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    Laramie

    The average temperature in December was 23.3°F. This is 2.0°F warmer than normal. The maximum temperature for the month was 50°F on the 6th and the minimum for the month was -5°F occurring on the 9th. Precipitation total of 0.22 inch is 48 percent of normal. Snowfall totaled 7.1 inches and is 109 percent of the long term mean. For 2004, the average temperature was 41.9°F or 1.5°F above normal. Precipitation totaled 8.99 inches or 79.1 percent of normal.

    Rawlins

    The average temperature in December was 25.3°F. This is 1.2°F warmer than normal. The maximum temperature for the month was 47°F on the 1st and the minimum for the month was 3°F occurring on the 15th. Precipitation total of just 0.08 inch is 16 percent of normal. Snowfall totaled 4.4 inches and is 58 percent of the long term average. For 2004, the average temperature was 44.1°F or exactly normal. Precipitation totaled 9.31 inches or 93.1 percent of normal.

    Rock Springs

    The average temperature in December was 22.8°F. This is 2.6°F warmer than normal. The maximum temperature for the month was 42°F on the 14th and the minimum for the month was 2°F occurring on the 24th. Precipitation total of 0.71 inch is 116 percent of normal. Snowfall totalled 12.2 inches and is 200 percent of the long term average. For 2004, the average temperature was 45.45°F or 3.65°F above normal. Precipitation totaled 6.66 inches or 70.4 percent of normal.

    Evanston

    The average temperature in December was 23.3°F. This is 2.5°F warmer than normal. The maximum temperature for the month was 43°F on the 1st and 20th and the minimum for the month was 2°F occurring on the 23rd. Precipitation total of 1.14 inches is 170 percent of normal. Snowfall totaled 22.7 inches and is 273 percent of the long term average and is the 3rd greatest December total since 1898. The record is held by December 1948 (27.0 inches). For 2004, the average temperature was 43.4°F or 3.1°F above normal. Precipitation totaled 11.61 inches or 101 percent of normal.

    Big Piney

    The average temperature in December was 13.3°F. This is 0.6°F warmer than normal. The maximum temperature for the month was 37°F on the 14th and the minimum for the month was -14°F occurring on the 29th. Precipitation total of 0.58 inch is 181 percent of normal. Snowfal totaled 12.2 inches and is 313 percent of the long term average and is the 5th greatest December total since 1948. For 2004, the average temperature was 37.5°F or 1.7°F above normal. Precipitation totaled 5.59 inches or 75.6 percent of normal.

    Lander

    The average temperature in December was 25.3°F. This is 4.0°F warmer than normal and represents the 30th warmest December since 1892. The maximum temperature for the month was 52°F on the 20th and the minimum for the month was -4°F occurring on the 29th. Precipitation total of 0.82 inch is 134 percent of normal. Snowfall totalled 17.3 inches and is 177 percent of the long term average. For 2004, the average temperature was 46.1°F or 1.1°F above normal. Precipitation totaled 10.26 inches or 76.5 percent of normal.

  • past 30-days precipitation
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    Riverton

    The average temperature in December was 23.9°F. This is 8.0°F warmer than normal and represents the 11th warmest December on record. The maximum temperature for the month was 53°F on the 14th and the minimum for the month of -4°F occurred on the 29th. Precipitation total of 0.31 inch is 86 percent of normal. Snowfall totaled 4.5 inches and is 102 percent of the long term average. For 2004, the average temperature was 45.9°F or 2.7°F above normal. Precipitation totaled 8.10 inches or 93.3 percent of normal.

    Worland

    The average temperature in December was 24.7°F. This is 4.8°F warmer than normal. The maximum temperature for the month was 57°F on the 14th and the minimum for the month of -14°F occurred on the 29th. Precipitation total of 0.69 inch is 225 percent of normal. Snowfall totaled 10.4 inches and is 186 percent of the long term average. For 2004, the average temperature was 46.35°F or 0.3°F below normal. Precipitation totaled 9.18 inches or 115.2 percent of normal.

    Sheridan

    The average temperature in December was 26.8°F. This is 4.8°F warmer than normal. The maximum temperature for the month was 57°F on the 14th and the minimum for the month of 1°F occurred on the 10th. Precipitation total of 0.87 inch is 128 percent of normal. Snowfall totaled 13.0 inches and is 117 percent of the long term average. For 2004, the average temperature was 46.1°F or 1.3°F above normal. Precipitation totaled 12.80 inches or 87.0 percent of normal.

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    Casper

    The average temperature in December was 29.0°F. This is 5.2°F warmer than normal and represents the 12th warmest December since 1940. The maximum temperature for the month was 52°F on the 20th and the minimum for the month of 3°F occurred on the 12th. Precipitation total of 0.39 inch is 63 percent of normal and represents the 29th driest December since 1940. Snowfall totalled 11.2 inches and is 109 percent of the long term average. For 2004, the average temperature was 46.1°F or 1.3°F above normal. Precipitation totaled 12.80 inches or 100.5 percent of normal.

  • past 30-days precipitation
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    Torrington

    The average temperature in December was 31.1°F. This is 4.9°F warmer than normal. The maximum temperature for the month was 63°F on the 6th and 7th and the minimum for the month of -2°F occurred on the 10th and 12th. Precipitation total of 0.30 inch is 83 percent of normal. Snowfall totalled 4.1 inches and is 77 percent of the long term average. For 2004, the average temperature was 49.9°F or 2.3°F above normal. Precipitation totaled 12.06 inches or 87.1 percent of normal.

    Additional Stations:

    Buffalo
    Douglas
    Gillette
    Greybull

    This information was compiled by the Wyoming State Climatologist, University of Wyoming. For more information, contact Jan Curtis at (307) 766-6659. For periodic updates, visit http://www.wrds.uwyo.edu This site includes a searchable database for Wyoming climate and water. For additional daily and hourly climatology, click on historical at the bottom of the daily summary statistics. For Casper, Lander, and Riverton's Monthly F6 reports, see here and at the bottom of this webpage. Record daily temperatures are based on the period since 1948-9 for all cities unless otherwise noted.

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    Wyoming State Climatologist The Wyoming State Climatologist Office is funded by the Wyoming Water Development Commission

    WEBMASTER: stateclim@wrds.uwyo.edu
    Last reviewed or update: January 6, 2004

    		 Water Resources Data System