Preliminary
Wyoming Monthly Climatology
September 2005

Statewide Summary

Graphs show that during the month of September, temperatures were below normal over the southwestern quadant of the state including Converse County and above normal elsewhere. Precipitation was above normal over the nothwestern and south central regions of the state and below normal elsewhere. During the month, modeled soil moisture showed some improvements over areas west of the Continental Division with dry conditions persisting across northeastern Wyoming. Stream flows were near normal except over portions of the North Platte River Basin and a few areas that border Montana. The end of September Drought Monitor map shows conditions varying from no drought to severe drought over Wyoming. Slight improvement & worsening across the state is noted during the 2005 Water Year.

As of October 2, 38 percent of the State had adequate topsoil moisture, 3 points below last week. Topsoil moisture was below adequate in the winter wheat growing areas of the state. Subsoil moisture supplies were rated 36 percent adequate, 7 points above last year at this time. Range and pasture lands were rated good or excellent in 51 percent of the state, up another 2 points from last week and well ahead of last year's 20 percent and the 5-year average of 11 percent. Grazing conditions were the best since 1999 at this time. Stock water supplies were adequate or better for the Western part of the state and were rated adequate in 58 percent of the entire state and surplus in 1 percent, compared to 40 percent adequate last year.

Weather Summary: For the week ending Friday, September 2. Daytime highs were mostly in the 80's to upper 90's, while night time temperatures were mostly in the 30's to low 40's. Temperatures have continued a cooling trend. Some western areas reached freezing temperatures. Very little precipitation fell throughout the state.

Weather Summary: For the week ending Friday, September 10th, temperatures averaged from 2.2 degrees above normal in Deaver to 10.6 degrees above normal in Douglas. Thehigh temperature was 98 in Sundance and the low was 30 in Big Piney. For the second consecutive week, there was very little precipitation reported. Rock Springs had 0.27 inches and Saratoga had 0.25 inches for the most precipitation.

Severe Weather:

12 2303 88H 13 E WRIGHT CAMPBELL WY (UNR)

13 0020 175H 1 N BILL CONVERSE WY HAIL LASTED FOR 5 MINUTES...UNTIL 625 PM. THE LARGE HAIL WAS BETWEEN 1 AND 3 MILES NORTH OF BILL AND COVERED THE GROUND TO A DEPTH OF 6 INCHES. (CYS)

13 0030 75H 4 N NEWCASTLE WESTON WY (UNR)

13 0110 175H 2 S BILL CONVERSE WY (CYS)

13 0020 60W 3 W NEWCASTLE WESTON WY (UNR)

Weather Summary: For the week ending Friday, September 17th, temperatures ranged from 6.6 degrees below normal in Afton to 3.6 degrees above normal in Cheyenne. The high temperature was 96 in Wheatland and the low was 21 in Big Piney. Precipitation was below normal except in some western areas. The most precipitation was reported in Rawlins had 0.58 inches, Rock Springs had 0.48 inches, and Big Piney had 0.37 inches.

Weather Summary: For the week ending Friday, September 23rd, temperatures ranged from 0.5 degrees above normal in Afton to 6.2 degrees above normal in Cheyenne. The high temperature was 91 in Torrington and the low was 21 in Jackson. Most areas received some rain but amounts were generally below normal. The most precipitation was reported in Jackson with 0.75 inches and Afton and Laramie with 0.36 inches.

Weather Summary: For the week ending Friday, September 30th, temperatures ranged from 2.0 degrees below normal in Afton to 4.3 degrees above normal in Laramie. The high temperature was 87 in Torrington and Wheatland and the low was 17 in Saratoga. Most areas received some rain, but amounts were generally below normal. The most precipitation was reported in Riverton with 0.65 inches followed by Deaver with 0.62 inches, Newcastle with 0.58 inches, and Powell with 0.57 inches.

24th Severe Weather: 0501 175H RIVERTON FREMONT WY 4304 10842 NUMEROUS REPORTS OF PENNY TO GOLFBALL SIZE HAIL REPORTED (RIW)

27th Severe Weather: 2017 59W LARAMIE ALBANY WY 4131 10558 (CYS)
2055 74W 12 W CHEYENNE LARAMIE WY 4115 10502 (CYS)
2113 58W CHEYENNE LARAMIE WY 4115 10479 (CYS)

Severe Weather Key: All Times UTC (MDT is 8 hours earlier), Wind (W) Gusts in MPH, Hail (H) Sizes in 1/100 of an Inch (75 = 0.75") and Tornado (TOR).

Cheyenne
Calendar

The average temperature in September was 62.1°F. This is 5.5°F warmer than normal for the month. The maximum temperature for the month was 89°F on the 3rd and the minimum of 35°F occurred on the 29th. Precipitation total of 0.24 inch is 17% of normal (11th driest on record since 1915). The wettest day in the month was on the 26th-27th (0.14 inch fell).

  • past 30-days precipitation
  • past 30-days temperature
  • past 90-days precipitation
  • past 90-days temperature
  • past 365-days precipitation
  • past 365-days temperature

    Laramie
    Calendar

    The average temperature in September was 55.6°F. This is 2.7°F warmer than normal for the month. The maximum temperature for the month was 82°F on the 3rd and the minimum of 28°F occurred on the 13th, 26th and 29th. Precipitation total of 0.43 inch is 43% of normal. The wettest day in the month was on the 21st (0.30 inch fell).

    Rawlins
    Calendar

    The average temperature in September was 56.8°F. This is 0.1°F cooler than normal for the month. The maximum temperature for the month was 85°F on the 3rd and the minimum for the month was 27°F occurring on the 26th and 29th. Precipitation total of 0.80 inch is 98% of normal. The wettest day in the month was on the 9th (0.50 inch fell).

    Rock Springs
    Calendar

    The average temperature in September was 56.1°F. This is 1.2°F warmer than normal for the month. The maximum temperature for the month was 82°F on the 2nd and 8th and the minimum for the month was 28°F occurring on the 13th. Precipitation total of 1.08 inches is 124% of normal. The wettest day in the month was on the 9th-10th (0.56 inch fell).

    Evanston
    Calendar

    The average temperature in September was 55.2°F. This is 2.4°F warmer than normal for the month. The maximum temperature for the month was 82°F on the 2nd and the minimum for the month was 29°F occurring on the 26th. Precipitation total of 0.46 inch is 36% of normal. The wettest day in the month was on the 21st (0.28 inch fell).

    Big Piney.
    Calendar

    The average temperature in September was 49.8°F. This is 1.3°F warmer than normal for the month. The maximum temperature for the month was 82°F on the 8th and the minimum for the month was 19°F occurring on the 26th. Precipitation total of 0.73 inch is 89% of normal. The wettest day in the month was on the 9th (0.27 inch fell).

    Lander
    Calendar

    The average temperature in September was 60.5°F. This is 1.48°F warmer than normal. The maximum temperature for the month was 89°F on the 2nd, 7th and 8th and the minimum for the month of 33°F occurred on the 13th and 26th. Precipitation total of 0.41 inch is 36% of normal. The wettest day in the month was on the 24th (0.29 inch fell).

  • past 30-days precipitation
  • past 30-days temperature
  • past 90-days precipitation
  • past 90-days temperature
  • past 365-days precipitation
  • past 365-days temperature

    Riverton
    Calendar

    The average temperature in September was 60.4°F. This is 3.1°F warmer than normal. The maximum temperature for the month was 90°F on the 8th and the minimum for the month of 33°F occurred on the 13th. Precipitation total of 0.68 inch is 77% of normal. The wettest day in the month was on the 24th (0.32 inch fell).

    Worland
    Calendar
    The average temperature in September was 59.6°F. This is 0.7°F cooler than normal for the month. The maximum temperature for the month was 93°F on the 8th and the minimum for the month of 34°F occurred on the 26th. Precipitation total of 0.68 inch is 80% of normal. The wettest day in the month was on the 24th (0.35 inch fell).

    Sheridan
    Click Preliminary Climatology Data F6 for Sheridan.
    Calendar

    The average temperature in September was 60.9°F. This is 3.1°F warmer than normal for the month. The maximum temperature for the month was 96°F on the 3rd and the minimum for the month of 32°F occurred on the 26th. Precipitation total of 0.71 inches is 51% of normal. The wettest day in the month was on the 12th (0.32 inch fell).

  • past 30-days precipitation
  • past 30-days temperature
  • past 90-days precipitation
  • past 90-days temperature
  • past 365-days precipitation
  • past 365-days temperature

    Casper
    Calendar

    The average temperature in September was 61.1°F. This is 3.5°F warmer than normal. The maximum temperature for the month was 92°F on the 8th (record for the day) and the minimum for the month of 33°F occurred on the 13th and 15th. Precipitation total of 0.23 inch is 23% of normal and represents the 11th driest September on record. The wettest day in the month was on the 24th (0.08 inch fell).

  • past 30-days precipitation
  • past 30-days temperature
  • past 90-days precipitation
  • past 90-days temperature
  • past 365-days precipitation
  • past 365-days temperature

    Douglas
    Calendar

    The average temperature in September was 61.4°F. This is 3.3°F warmer than normal for the month. The maximum temperature for the month was 94°F on the 8th and the minimum for the month of 30°F occurred on the 29th. Precipitation total of 0.65 inch is 61% of normal. The wettest day in the month was on the 24th-25th (0.38 inch fell).

    Torrington
    Calendar

    The average temperature in September was 63.9°F. This is 4.1°F warmer than normal for the month. The maximum temperature for the month was 96°F on the 3rd and 8th and the minimum for the month of 30°F occurred on the 29th. Precipitation total of 0.3 inch is 24% of normal. The wettest day in the month was on the 21st (0.20 inch fell).

    Additional Summaries:

    Buffalo (Calendar)
    Cody
    Gillette or
    Click Automated Monthly Data F6 for more Gillette data (Calendar)
    Greybull (Calendar)
    Jackson (Calendar)
    Yellowstone Lake (Calendar)

    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.

    To Wyoming Monthly Summaries Index Listing

    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: October 3, 2005

    		 Water Resources Data System