Casper, WY

Wyoming · Records since 1939–2026

🌤️ 80°F Feels like 71°
Currently in Casper
As of 12:30 PM MDT

Records for September 7

🔥 Record High

96°F

September 7, 2022

+16° from 80° normal

❄ Record Low

28°F

September 7, 2010

-17° from 45° normal
🌞 Normal high: 80°F 🌑 Normal low: 45°F 1991–2020 normals

All-Time Records — Casper

🔥
104°F
Hottest Day Ever
Jul 29, 2006
❄
-42°F
Coldest Day Ever
Dec 22, 2022
🌧
2.80"
Wettest Day Ever
Apr 13, 1941
☃
26.7"
Most Snow in One Day
Apr 3, 2023

Top 10 Record Highs — September 7

# Temp Date
🏆 96°F September 7, 2022
2 94°F September 7, 1978
3 93°F September 7, 1998
4 92°F September 7, 1983
5 92°F September 7, 1959
6 91°F September 7, 2013
7 91°F September 7, 1988
8 91°F September 7, 1979
9 91°F September 7, 1977
10 90°F September 7, 1955

Top 5 Record Lows — September 7

# Temp Date
🥶 28°F September 7, 2010
2 31°F September 7, 2020
3 36°F September 7, 2000
4 36°F September 7, 1996
5 38°F September 7, 1999
About this data — Records are sourced from the NOAA Threadex dataset via RCC ACIS, a quality-controlled record for long-term climate stations. Threadex adjusts for station relocations and observation-time changes, making records comparable across all years since 1939–2026. Climate normals represent the 1991–2020 average.

Heat Wave Summary — Casper

threshold: 94°F (90th percentile of historical Jun–Aug highs)
4.1
Avg heat wave length
days (historical)
98°
Avg peak temp
during heat waves
0
Dangerous nights 2026
Overnights ≥ 70°F
5
Heat waves 2026
so far

2026 Daily High Temperature vs Normal

Year to date
Above normal Below normal

179 of 249 days with data were above the 1991–2020 normal high for their date.

Days ≥ 90°F Per Year

1940–2026
50
2026 so far
32
Avg/year 1970–2025
42
Avg/year (last 10 complete)
57
Most in a year (1988)

Average Daily High by Decade

Full year · complete decades only

Longest Heat Waves — Casper

# Dates Days Peak Avg High Avg Overnight Low
🏆 Jul 10, 2026 – Jul 20, 2026 11 103°F (Jul 12) 98°F 57°F
2 Jul 15, 2007 – Jul 25, 2007 11 99°F (Jul 17) 96°F 59°F
3 Jun 23, 1990 – Jul 2, 1990 10 102°F (Jun 30) 99°F 57°F
4 Jun 25, 2002 – Jul 3, 2002 9 100°F (Jun 30) 96°F 53°F
5 Aug 6, 2003 – Aug 14, 2003 9 99°F (Aug 14) 97°F 60°F
6 Jun 20, 1988 – Jun 27, 1988 8 102°F (Jun 24) 98°F 65°F
7 Jul 3, 1989 – Jul 9, 1989 7 102°F (Jul 8) 98°F 58°F
8 Aug 2, 2001 – Aug 8, 2001 7 101°F (Aug 6) 97°F 62°F
9 Jul 19, 2014 – Jul 25, 2014 7 100°F (Jul 23) 96°F 55°F
10 Jul 19, 2005 – Jul 24, 2005 6 103°F (Jul 22) 98°F 58°F

Heat Waves Per Year

Warm Summer Nights (Jun–Aug)

Nights where the overnight low exceeded the 1991–2020 normal low

58
2026 total
above-normal nights
47.3
Avg / summer
1970–2020
77
Most in a summer
1961

Above-Normal Summer Nights Per Year

Average June–August Low by Decade

Overnight lows · complete decades only

Precipitation

Actual vs. 1991–2020 full-month and full-season normals

6.35"
2026 YTD
Normal: 8.96"
-2.61"
0.01"
September so far
September normal: 0.95"
-0.94"
1
2026 heavy rain days
Days with ≥ 1.0"

2026 Accumulation vs. Normal

Running total since Jan 1 against the normal pace for the same date · Casper is 2.61" behind the normal pace

Monthly Precipitation — Last 24 Months

Blue = actual · dashed line = monthly normal

Annual Precipitation Per Year (1939–2026)

Blue = above average · tan = below average · gold = 2026 (partial)
Since 1939, annual totals have trended +0.27" per decade, about +2.3" across the record.

Heavy Rain Days Per Year (≥ 1.0")

Compare year-to-year changes in days with heavy rainfall (≥ 1.0")

Month in Review — August 2026

71.5°F

Average temperature · August 2026

55th-warmest month on record

16th-warmest August of 87 on record

+2.1° vs. 69.4° average (1991–2020)
76.1°F
Warmest month ever
July 1954
74.7°F
Warmest August ever
1983
14
Days ≥ 90°F
in August
103°F
Hottest of 2026
Jul 12

Longest 90°F Streak in August

6 consecutive days with highs of at least 90°F (Aug 6–11, 2026, peaking at 99°F)

Ties the longest August streak since 2024 (2 years). The August record is 13 days, set in 2020.

Average August Temperature by Year

1940–2026 · 2026 highlighted

Precipitation — August 2026

Month total against the 1991–2020 average and every other August on record

2.01"
Total precipitation
August 2026
+1.22"
vs. average
Normal: 0.79" · 254% of normal
5th-wettest
August rank
of 87 on record
2.79"
Wettest August ever
1941 · driest 0.00" (1944)

August Precipitation by Year

1940–2026 · 2026 highlighted · trend +0.05" per decade (wetter since 1940)

Wettest Augusts on Record

# Year Total
1 1941 2.79"
2 1979 2.66"
3 2007 2.57"
4 2005 2.24"
5 2026 2.01"
6 2022 1.99"
7 1990 1.89"
8 1987 1.80"
9 2003 1.68"
10 1972 1.52"

Driest Augusts on Record

# Year Total
1 1944 0.00"
2 1950 0.02"
3 1995 0.04"
4 2020 0.05"
5 1961 0.08"
6 1985 0.09"
7 1943 0.09"
8 1951 0.10"
9 1999 0.11"
10 1971 0.11"

Warmest Augusts on Record

# Year Avg Temp
1 1983 74.7°F
2 1982 73.7°F
3 1994 73.4°F
4 1955 73.2°F
5 1995 72.6°F
6 2003 72.4°F
7 2000 72.4°F
8 1970 72.2°F
9 1961 72.1°F
10 2001 72.0°F

Warmest Months on Record (Any Month)

# Month Avg Temp
1 July 1954 76.1°F
2 July 2026 75.8°F
3 July 2006 75.3°F
4 July 2012 75.2°F
5 July 1966 74.9°F
6 July 2007 74.8°F
7 August 1983 74.7°F
8 July 1964 74.1°F
9 July 1940 73.9°F
10 July 2001 73.8°F

Nearby Stations — August 2026

How the same month ranked at the closest reporting stations

Station Avg Temp August Rank
Casper, WY 71.5°F 16th of 87
Lander, WY 72.6°F 13th of 135
Sheridan, WY 69.5°F 50th of 120
Cheyenne, WY 71.1°F 5th of 154
Scottsbluff, NE 74.9°F 15th of 130
About this data. Monthly averages are the mean of daily average temperatures, computed from NOAA Threadex records via RCC ACIS. Months missing more than three days of observations are excluded from the rankings, so the in-progress month never appears. Rankings cover 1,041 complete months on record. Precipitation totals sum the daily reports for the month, with trace amounts counted as zero. A month missing any day of precipitation data is left out entirely (an unreported day is unreported rain), so the precipitation ranking covers 87 complete Augusts. Normals are the 1991–2020 mean for the same calendar month. Trend lines are a least-squares fit across every year shown.

Fall in Review — Fall 2026

September 1 – November 30, 2026

Fall 2026 is still under way. Season totals and rankings appear once November closes; the markers below update as they happen.

Summer to Winter — 2026

Each turning point of the season against its 1991–2020 normal date, with the earliest and latest on record

Marker 2026 Normal vs. normal Earliest Latest Drift
Last 90°F day
The final day of summer heat
 Sep 6
so far
 Sep 8 Aug 7, 1968 Sep 29, 2024 +2.0 d/decade
Last 80°F day
The last genuinely warm afternoon
 Sep 6
so far
 Oct 1 Sep 8, 1986 Oct 23, 2003 +0.1 d/decade
First high below 50°F
The first afternoon that stays cold
 not yet Sep 29 Sep 1, 1974 Oct 31, 1963 +0.5 d/decade
First 32°F freeze
Growing season over
 not yet Sep 19 Jul 4, 1972 Oct 28, 1940 -1.1 d/decade
First 28°F hard freeze
Cold enough to end tender growth
 not yet Sep 30 Sep 7, 2010 Nov 4, 1940 -0.8 d/decade
First 20°F night
Winter cold arriving
 not yet Oct 22 Sep 16, 1965 Nov 18, 1962 -0.1 d/decade
First measurable snow
0.1" or more in a day
 not yet Oct 6 Sep 8, 1962 Dec 30, 2024 +1.2 d/decade

Drift is a least-squares fit across every year on record. Positive means the marker has been arriving later.

First Freeze by Year

The first 32°F night of each autumn since 1940 · trending -1.1 days earlier per decade

118
Normal length
1991–2020 average
165
Longest on record
1963
34
Shortest on record
1972

Growing Season Length by Year

Days between the last spring freeze and the first fall freeze · trending -2.0 days shorter per decade

Fall Average Temperature by Year

1940–2025 · 2026 highlighted

Fall Precipitation by Year

1940–2025 · 2026 highlighted · trend +0.05" per decade (wetter since 1940)

About this data. Fall is meteorological autumn, September 1 through November 30, the window NOAA uses for seasonal statistics. Seasonal temperature is the day-weighted mean of the three monthly means; precipitation is their sum, and a season missing any of the three months is left out of the rankings. Freeze, heat and snow markers come from daily NOAA Threadex observations via RCC ACIS: freezes and snow are the first occurrence on or after July 1, and the last 90°F and 80°F days are the final ones anywhere in the calendar year. Growing season counts the freeze-free days between the last spring 32°F and the first fall 32°F.
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