Flagstaff Weather in September
Average highs run from 78°F on September 1 to 70°F on September 30, and lows from 47°F to 37°F. Normal precipitation for the month is 1.84 in over about 8 wet days.
September day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
September at a glance
- Average high
- 74°F
- Average low
- 43°F
- Precipitation
- 1.84 in
- Record high
- 91°FSep 6, 2020
- Record low
- 22°FSep 26, 1934
- Chance of a freeze
- 59%
- Daylight
- 12 h 54 min to 11 h 51 min
- Cloud cover
- 34%
- Humidity
- 46%
- Dew point
- 40°F
- Wind
- 7.6 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Sep 1 | 78°F | 47°F | 90°F 1950 | 33°F 1962 | 36% | 0% |
| Sep 2 | 78°F | 47°F | 88°F 1982 | 35°F 1953 | 35% | 0% |
| Sep 3 | 77°F | 47°F | 89°F 2020 | 34°F 1961 | 34% | 0% |
| Sep 4 | 77°F | 47°F | 90°F 2020 | 27°F 1961 | 34% | 0% |
| Sep 5 | 77°F | 46°F | 90°F 2020 | 31°F 1961 | 33% | 0% |
| Sep 6 | 77°F | 46°F | 91°F 2020 | 33°F 1985 | 32% | 0% |
| Sep 7 | 77°F | 46°F | 89°F 1977 | 35°F 1970 | 32% | 0% |
| Sep 8 | 76°F | 45°F | 88°F 1977 | 33°F 1935 | 31% | 0% |
| Sep 9 | 76°F | 45°F | 87°F 1977 | 31°F 1941 | 30% | 0% |
| Sep 10 | 76°F | 45°F | 87°F 1990 | 26°F 2020 | 30% | 0% |
| Sep 11 | 76°F | 44°F | 88°F 1990 | 30°F 1986 | 29% | 0% |
| Sep 12 | 75°F | 44°F | 88°F 1990 | 25°F 1985 | 28% | 0% |
| Sep 13 | 75°F | 44°F | 89°F 1990 | 26°F 1952 | 27% | 0% |
| Sep 14 | 75°F | 43°F | 88°F 2000 | 29°F 1988 | 27% | 0% |
| Sep 15 | 75°F | 43°F | 87°F 1956 | 30°F 1970 | 26% | |
| Sep 16 | 74°F | 43°F | 88°F 2000 | 28°F 1906 | 25% | |
| Sep 17 | 74°F | 42°F | 88°F 1956 | 30°F 1970 | 25% | |
| Sep 18 | 74°F | 42°F | 86°F 1956 | 27°F 2006 | 24% | |
| Sep 19 | 73°F | 41°F | 84°F 1956 | 25°F 1971 | 23% | |
| Sep 20 | 73°F | 41°F | 83°F 2000 | 23°F 1971 | 23% | |
| Sep 21 | 73°F | 41°F | 81°F 1954 | 23°F 1955 | 22% | |
| Sep 22 | 72°F | 40°F | 80°F 1966 | 27°F 1895 | 21% | |
| Sep 23 | 72°F | 40°F | 83°F 1982 | 25°F 1970 | 21% | |
| Sep 24 | 72°F | 39°F | 82°F 1982 | 25°F 2017 | 20% | |
| Sep 25 | 71°F | 39°F | 83°F 1991 | 24°F 1959 | 20% | |
| Sep 26 | 71°F | 39°F | 84°F 2024 | 22°F 1934 | 20% | |
| Sep 27 | 71°F | 38°F | 85°F 2024 | 26°F 1934 | 19% | |
| Sep 28 | 70°F | 38°F | 86°F 2024 | 24°F 1934 | 19% | |
| Sep 29 | 70°F | 37°F | 84°F 2024 | 26°F 1894 | 19% | |
| Sep 30 | 70°F | 37°F | 84°F 2024 | 27°F 1927 | 18% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (MST).
- September 1
- sunrise 5:59 AM, sunset 6:53 PM
- September 30
- sunrise 6:21 AM, sunset 6:12 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00003103 (Flagstaff Pulliam AP), public domain. Records: NOAA GHCN-Daily, station USW00003103, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.