September weather in Flagstaff, AZ
The average temperature in Flagstaff in September is 58.3°F (42.5°F–74.1°F). Average precipitation: 1.84 inches.
September is a fall month in Flagstaff, and is warmer than the annual average of 46.8°F. Daily temperatures swing about 31.6°F between overnight low and afternoon high. Expect about 8 days with precipitation. Daylight averages about 12h 13m. For travel, September is a comfortable month to visit.
Avg High
74.1°F
Avg Low
42.5°F
Precipitation
1.84 in
Daylight
12h 13m
September records in Flagstaff
| Date | Record High | Record Low | Record Precip |
|---|---|---|---|
| September 1 | 90.0°F (1950) | 33.1°F (1962) | 1.32 in (1998) |
| September 2 | 88.0°F (1982) | 35.1°F (1953) | 0.86 in (1990) |
| September 3 | 89.1°F (2020) | 34.0°F (1961) | 0.49 in (1940) |
| September 4 | 90.0°F (2020) | 27.0°F (1961) | 0.65 in (1970) |
| September 5 | 90.0°F (2020) | 30.9°F (1961) | 2.84 in (1970) |
| September 6 | 91.0°F (2020) | 33.1°F (1985) | 0.82 in (2002) |
| September 7 | 89.1°F (1977) | 35.1°F (1970) | 1.08 in (2002) |
| September 8 | 88.0°F (1977) | 33.1°F (1935) | 1.07 in (2011) |
| September 9 | 87.1°F (1977) | 30.9°F (1941) | 1.61 in (2003) |
| September 10 | 87.1°F (1990) | 26.2°F (2020) | 1.40 in (1924) |
| September 11 | 88.0°F (1990) | 30.0°F (1986) | 1.97 in (1985) |
| September 12 | 88.0°F (1990) | 25.0°F (1985) | 1.80 in (1927) |
| September 13 | 89.1°F (1990) | 26.1°F (1952) | 2.75 in (1941) |
| September 14 | 88.0°F (2000) | 28.9°F (1988) | 1.50 in (1999) |
| September 15 | 87.1°F (1956) | 30.0°F (1970) | 0.54 in (1906) |
| September 16 | 88.0°F (2000) | 28.0°F (1906) | 1.29 in (2007) |
| September 17 | 88.0°F (1956) | 30.0°F (1970) | 1.71 in (1925) |
| September 18 | 86.0°F (1956) | 27.0°F (2006) | 2.11 in (1965) |
| September 19 | 84.0°F (1956) | 25.0°F (1971) | 1.03 in (2004) |
| September 20 | 82.9°F (2000) | 23.0°F (1971) | 1.52 in (1952) |
| September 21 | 81.0°F (1954) | 23.0°F (1955) | 0.81 in (1990) |
| September 22 | 80.1°F (1966) | 27.0°F (1895) | 1.03 in (1958) |
| September 23 | 82.9°F (1982) | 25.0°F (1970) | 2.71 in (1983) |
| September 24 | 82.0°F (1982) | 25.2°F (2017) | 1.20 in (1967) |
| September 25 | 82.9°F (1991) | 24.1°F (1959) | 1.00 in (1986) |
| September 26 | 84.0°F (2024) | 21.9°F (1934) | 1.35 in (1997) |
| September 27 | 84.9°F (2024) | 26.1°F (1934) | 0.73 in (1987) |
| September 28 | 86.0°F (2024) | 24.1°F (1934) | 1.79 in (1958) |
| September 29 | 84.0°F (2024) | 26.1°F (1894) | 1.94 in (1905) |
| September 30 | 84.0°F (2024) | 27.0°F (1927) | 1.75 in (1983) |