September weather in Riverton, WY
The average temperature in Riverton in September is 58.4°F (42.5°F–74.4°F). Average precipitation: 0.80 inches. Average snowfall is 0.6 inches.
September is a fall month in Riverton, and is warmer than the annual average of 43.9°F. Daily temperatures swing about 31.9°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
74.4°F
Avg Low
42.5°F
Precipitation
0.80 in
Snow
0.6 in
September records in Riverton
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 96.1°F (1954) | 33.1°F (1924) | 0.31 in (1963) |
| September 2 | 95.0°F (2022) | 33.1°F (1952) | 1.50 in (1973) |
| September 3 | 95.0°F (1987) | 30.0°F (1961) | 0.35 in (1943) |
| September 4 | 97.0°F (1950) | 30.9°F (1984) | 1.18 in (1999) |
| September 5 | 98.1°F (2022) | 33.1°F (1953) | 0.23 in (1929) |
| September 6 | 97.0°F (2020) | 28.9°F (1943) | 1.04 in (1981) |
| September 7 | 95.0°F (1908) | 30.0°F (1989) | 0.48 in (1946) |
| September 8 | 98.1°F (1990) | 30.0°F (1929) | 0.63 in (2020) |
| September 9 | 95.0°F (1979) | 24.1°F (1962) | 0.94 in (1912) |
| September 10 | 93.9°F (2021) | 28.9°F (1992) | 0.62 in (1912) |
| September 11 | 90.0°F (1997) | 26.1°F (1918) | 1.16 in (1973) |
| September 12 | 91.0°F (1948) | 28.0°F (1951) | 0.93 in (2019) |
| September 13 | 96.1°F (1990) | 25.0°F (1974) | 0.89 in (1998) |
| September 14 | 91.0°F (1948) | 21.9°F (1993) | 1.50 in (1982) |
| September 15 | 96.1°F (1948) | 27.0°F (1936) | 0.60 in (1966) |
| September 16 | 93.0°F (2000) | 23.0°F (1936) | 0.54 in (2022) |
| September 17 | 93.0°F (2000) | 23.0°F (1965) | 0.34 in (1923) |
| September 18 | 88.0°F (1937) | 10.0°F (1965) | 0.95 in (1978) |
| September 19 | 95.0°F (1981) | 15.1°F (1965) | 0.68 in (1961) |
| September 20 | 91.0°F (1981) | 23.0°F (1965) | 1.54 in (1950) |
| September 21 | 90.0°F (1956) | 19.0°F (1983) | 1.08 in (1989) |
| September 22 | 87.1°F (1936) | 23.0°F (1983) | 0.45 in (1960) |
| September 23 | 87.1°F (1947) | 23.0°F (1984) | 0.75 in (2016) |
| September 24 | 90.0°F (1992) | 19.0°F (1984) | 1.04 in (1912) |
| September 25 | 88.0°F (2020) | 9.0°F (1926) | 0.85 in (1955) |
| September 26 | 91.0°F (2024) | 16.0°F (1926) | 0.43 in (1936) |
| September 27 | 89.1°F (2014) | 19.0°F (1908) | 2.14 in (1923) |
| September 28 | 88.0°F (2001) | 14.0°F (1984) | 1.79 in (1923) |
| September 29 | 88.0°F (1994) | 12.9°F (1984) | 0.55 in (2014) |
| September 30 | 91.0°F (2024) | 17.1°F (1984) | 0.97 in (1944) |