Arapahoe Weather in September
Average highs run from 85°F on September 1 to 75°F on September 30, and lows from 55°F to 43°F. Normal precipitation for the month is 1.90 in over about 7 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
- 81°F
- Average low
- 49°F
- Precipitation
- 1.90 in
- Record high
- 107°FSep 1, 1985
- Record low
- 18°FSep 29, 1984
- Chance of a freeze
- 28%
- Days of 90°F or more
- 7.4
- Daylight
- 13 h 04 min to 11 h 48 min
- Cloud cover
- 45%
- Humidity
- 56%
- Dew point
- 49°F
- Wind
- 11.0 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 | 85°F | 55°F | 107°F 1985 | 37°F 1949 | 28% | 0% |
| Sep 2 | 85°F | 55°F | 104°F 1947 | 40°F 1952 | 27% | 0% |
| Sep 3 | 85°F | 54°F | 104°F 1954 | 31°F 1974 | 27% | 0% |
| Sep 4 | 85°F | 54°F | 105°F 1945 | 40°F 1905 | 27% | 0% |
| Sep 5 | 84°F | 53°F | 103°F 1976 | 34°F 1962 | 26% | 0% |
| Sep 6 | 84°F | 53°F | 104°F 1984 | 33°F 1956 | 26% | 0% |
| Sep 7 | 84°F | 53°F | 104°F 2013 | 37°F 2010 | 26% | 0% |
| Sep 8 | 84°F | 52°F | 104°F 1955 | 38°F 2012 | 26% | 0% |
| Sep 9 | 83°F | 52°F | 104°F 1955 | 34°F 1943 | 26% | 0% |
| Sep 10 | 83°F | 52°F | 99°F 2013 | 33°F 1959 | 26% | 0% |
| Sep 11 | 83°F | 51°F | 102°F 1911 | 34°F 1945 | 25% | 0% |
| Sep 12 | 83°F | 51°F | 104°F 1911 | 36°F 1913 | 25% | 0% |
| Sep 13 | 82°F | 50°F | 106°F 1911 | 31°F 1949 | 25% | 0% |
| Sep 14 | 82°F | 50°F | 99°F 2000 | 29°F 1945 | 25% | 0% |
| Sep 15 | 82°F | 50°F | 102°F 1955 | 29°F 1916 | 25% | 0% |
| Sep 16 | 81°F | 49°F | 105°F 1952 | 25°F 1903 | 25% | 0% |
| Sep 17 | 81°F | 49°F | 102°F 1983 | 25°F 1903 | 25% | 0% |
| Sep 18 | 80°F | 48°F | 101°F 1907 | 33°F 2012 | 24% | 0% |
| Sep 19 | 80°F | 48°F | 100°F 1947 | 31°F 1971 | 24% | 0% |
| Sep 20 | 80°F | 48°F | 99°F 2022 | 30°F 1943 | 24% | 0% |
| Sep 21 | 79°F | 47°F | 101°F 2022 | 24°F 1983 | 24% | 0% |
| Sep 22 | 79°F | 47°F | 97°F 2017 | 29°F 1995 | 24% | 0% |
| Sep 23 | 78°F | 46°F | 100°F 1954 | 30°F 1989 | 24% | 0% |
| Sep 24 | 78°F | 46°F | 94°F 2003 | 26°F 1965 | 24% | 0% |
| Sep 25 | 78°F | 46°F | 100°F 1998 | 26°F 1913 | 24% | 0% |
| Sep 26 | 77°F | 45°F | 96°F 1983 | 23°F 1913 | 23% | 0% |
| Sep 27 | 77°F | 45°F | 99°F 1952 | 28°F 1964 | 23% | 0% |
| Sep 28 | 76°F | 44°F | 102°F 1953 | 26°F 1951 | 23% | 0% |
| Sep 29 | 76°F | 44°F | 97°F 1952 | 18°F 1984 | 23% | 0% |
| Sep 30 | 75°F | 43°F | 103°F 1952 | 19°F 1984 | 23% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- September 1
- sunrise 7:07 AM, sunset 8:11 PM
- September 30
- sunrise 7:35 AM, sunset 7:23 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00252560 (Edison), public domain. Records: NOAA GHCN-Daily, station USC00251415, 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.