Casper September Weather

Averages and records for weather in Casper, Wyoming in the month of September.
Typical Casper September Weather
1991–2020
Average daily high 75.8 °F
Average daily low 42.6 °F
Average monthly precipitation 1.0 inches
Average monthly snow 1.5 inches
Daily chance of precipitation 22.8%
Daily chance of snow 1.7%
Casper September Weather Records
1900–2024
Highest temperature 103 °F September 19, 1911
Lowest temperature 14 °F September 25, 1926
Highest daily low 70 °F September 2, 1925
Lowest daily high 27 °F September 24, 1984
Hottest average high temperature 94.2 °F 1911
Coldest average high temperature 61.2 °F 1965
Most daily precipitation 2.7 inches September 28, 1923
Most monthly precipitation 5.1 inches 1923
Most daily snow 6.9 inches September 20, 1995
Most monthly snow 11.5 inches 2000
Note: Daily averages are a moving average which includes 14 days before and after
Day Average (°F) Record (°F)
High Low High Low
September 1 82.5 48.0 100 32
September 2 82.3 47.8 100 32
September 3 82.0 47.6 100 31
September 4 81.6 47.2 100 34
September 5 81.1 46.8 101 34
September 6 80.5 46.3 96 31
September 7 79.9 45.9 100 28
September 8 79.4 45.5 96 29
September 9 78.8 45.1 95 24
September 10 78.2 44.6 95 27
September 11 77.7 44.2 100 26
September 12 77.3 43.7 95 25
September 13 76.8 43.3 99 23
September 14 76.3 43.0 102 25
September 15 76.0 42.7 101 25
September 16 75.6 42.4 97 19
September 17 75.1 42.1 99 19
September 18 74.5 41.7 101 19
September 19 73.9 41.3 103 23
September 20 73.2 40.8 100 16
September 21 72.5 40.4 100 21
September 22 72.0 40.0 87 25
September 23 71.6 39.6 90 24
September 24 71.1 39.2 100 18
September 25 70.5 38.8 98 14
September 26 70.0 38.4 91 15
September 27 69.6 38.1 89 21
September 28 69.1 37.7 92 18
September 29 68.6 37.3 87 18
September 30 68.1 36.9 88 17
Weather Station Details
Years Station Coordinates
1949–2024 Casper-Natrona County International Airport location
1900–1948 Casper 2 E location