September weather in East Thermopolis, WY
The average temperature in East Thermopolis in September is 62.7°F (45.7°F–79.7°F). Average precipitation: 1.21 inches. Average snowfall is 0.3 inches.
September is a fall month in East Thermopolis, and is warmer than the annual average of 48.6°F. Daily temperatures swing about 34°F between overnight low and afternoon high. Expect about 5 days with precipitation. Daylight averages about 12h 17m. For travel, September is a comfortable month to visit.
Avg High
79.7°F
Avg Low
45.7°F
Precipitation
1.21 in
Snow
0.3 in
September records in East Thermopolis
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 99.0°F (2022) | 28.9°F (1920) | 0.80 in (2008) |
| September 2 | 99.0°F (2019) | 33.1°F (1924) | 0.35 in (1934) |
| September 3 | 99.0°F (1950) | 33.1°F (1920) | 0.79 in (1949) |
| September 4 | 102.0°F (2022) | 33.1°F (1920) | 0.88 in (1999) |
| September 5 | 102.9°F (2022) | 33.1°F (1920) | 0.40 in (1912) |
| September 6 | 102.0°F (2020) | 32.0°F (1929) | 0.55 in (1929) |
| September 7 | 104.0°F (2022) | 33.1°F (1953) | 1.07 in (2020) |
| September 8 | 102.0°F (2022) | 30.0°F (1910) | 0.25 in (1927) |
| September 9 | 98.1°F (2021) | 28.0°F (1922) | 0.86 in (1940) |
| September 10 | 97.0°F (2021) | 30.0°F (1962) | 0.78 in (1912) |
| September 11 | 96.1°F (2021) | 26.1°F (1916) | 1.12 in (2019) |
| September 12 | 96.1°F (1959) | 28.0°F (1951) | 0.40 in (2016) |
| September 13 | 95.0°F (1990) | 28.0°F (1914) | 0.77 in (1998) |
| September 14 | 95.0°F (1959) | 25.0°F (1952) | 0.56 in (1917) |
| September 15 | 93.9°F (2000) | 21.9°F (1916) | 1.00 in (2017) |
| September 16 | 96.1°F (2000) | 23.0°F (1936) | 0.58 in (2006) |
| September 17 | 96.1°F (2000) | 26.1°F (1936) | 1.90 in (1923) |
| September 18 | 93.0°F (1920) | 27.0°F (1936) | 0.53 in (2002) |
| September 19 | 95.0°F (1937) | 28.9°F (1911) | 0.80 in (1948) |
| September 20 | 93.9°F (1937) | 28.0°F (1913) | 0.93 in (1950) |
| September 21 | 95.0°F (1917) | 26.1°F (1924) | 0.87 in (1925) |
| September 22 | 91.9°F (1938) | 27.0°F (1955) | 0.85 in (2025) |
| September 23 | 93.0°F (1936) | 24.1°F (1955) | 1.18 in (1913) |
| September 24 | 91.0°F (1992) | 18.0°F (1926) | 0.43 in (1927) |
| September 25 | 95.0°F (2024) | 7.0°F (1926) | 1.04 in (1908) |
| September 26 | 95.0°F (2024) | 14.0°F (1926) | 0.55 in (1915) |
| September 27 | 93.9°F (2024) | 17.1°F (1926) | 1.90 in (2013) |
| September 28 | 93.9°F (2024) | 21.0°F (1920) | 0.28 in (1940) |
| September 29 | 93.0°F (1938) | 21.9°F (1926) | 0.77 in (1940) |
| September 30 | 91.0°F (1917) | 19.0°F (1920) | 4.94 in (1923) |