September weather in Fort Collins, CO
The average temperature in Fort Collins in September is 62.7°F (48.0°F–77.4°F). Average precipitation: 1.43 inches. Average snowfall is 0.7 inches.
September is a fall month in Fort Collins, and is warmer than the annual average of 50.7°F. Daily temperatures swing about 29.4°F between overnight low and afternoon high. Expect about 7 days with precipitation. Daylight averages about 12h 15m. For travel, September is a comfortable month to visit.
Avg High
77.4°F
Avg Low
48.0°F
Precipitation
1.43 in
Snow
0.7 in
September records in Fort Collins
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 96.1°F (2019) | 36.0°F (1956) | 0.94 in (1999) |
| September 2 | 99.0°F (2019) | 37.9°F (1905) | 1.14 in (1938) |
| September 3 | 98.1°F (2017) | 35.1°F (1934) | 3.54 in (1938) |
| September 4 | 93.9°F (1948) | 37.0°F (1902) | 0.95 in (1909) |
| September 5 | 97.0°F (2019) | 37.0°F (1962) | 0.83 in (1915) |
| September 6 | 99.0°F (2020) | 30.9°F (1943) | 0.62 in (1901) |
| September 7 | 93.9°F (2022) | 30.0°F (1898) | 1.64 in (1935) |
| September 8 | 96.1°F (2022) | 32.0°F (2020) | 1.19 in (2020) |
| September 9 | 96.1°F (2021) | 28.0°F (1929) | 1.53 in (1940) |
| September 10 | 98.1°F (2021) | 30.9°F (1907) | 0.79 in (1933) |
| September 11 | 96.1°F (2021) | 33.1°F (1898) | 1.29 in (1988) |
| September 12 | 91.9°F (2018) | 21.9°F (1902) | 1.99 in (2013) |
| September 13 | 97.0°F (1990) | 27.0°F (1902) | 1.70 in (1925) |
| September 14 | 93.0°F (1895) | 26.1°F (1914) | 1.07 in (1982) |
| September 15 | 91.9°F (1948) | 26.1°F (1903) | 1.17 in (1918) |
| September 16 | 95.0°F (1895) | 28.0°F (1903) | 0.82 in (1906) |
| September 17 | 93.9°F (1895) | 27.0°F (1965) | 1.62 in (1971) |
| September 18 | 93.9°F (1895) | 30.0°F (1903) | 0.83 in (1993) |
| September 19 | 91.0°F (1980) | 21.0°F (1971) | 0.88 in (1906) |
| September 20 | 93.9°F (1956) | 28.0°F (1983) | 1.88 in (1902) |
| September 21 | 88.0°F (1898) | 26.1°F (1983) | 4.34 in (1902) |
| September 22 | 89.1°F (1958) | 24.1°F (1995) | 1.40 in (1910) |
| September 23 | 90.0°F (1905) | 27.0°F (1895) | 1.22 in (2025) |
| September 24 | 87.1°F (2011) | 27.0°F (1965) | 0.79 in (2000) |
| September 25 | 90.0°F (1898) | 19.9°F (1926) | 0.45 in (1955) |
| September 26 | 90.0°F (2001) | 21.9°F (1942) | 1.92 in (2012) |
| September 27 | 90.0°F (1898) | 23.0°F (1908) | 0.81 in (2004) |
| September 28 | 91.0°F (2011) | 24.1°F (1985) | 0.92 in (1894) |
| September 29 | 88.0°F (2024) | 21.9°F (1985) | 0.52 in (1959) |
| September 30 | 87.1°F (1899) | 18.0°F (1985) | 0.72 in (1945) |