Arapahoe Weather in September
Average highs run from 85°F on September 1 to 79°F on September 30, and lows from 67°F to 59°F. Normal precipitation for the month is 7.14 in over about 10 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
- 82°F
- Average low
- 64°F
- Precipitation
- 7.14 in
- Record high
- 100°FSep 6, 1954
- Record low
- 45°FSep 23, 2020
- Chance of a freeze
- 0%
- Days of 90°F or more
- 2.6
- Daylight
- 12 h 54 min to 11 h 52 min
- Cloud cover
- 55%
- Humidity
- 80%
- Dew point
- 67°F
- Wind
- 7.4 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 | 67°F | 97°F 1993 | 58°F 1965 | 35% | 0% |
| Sep 2 | 85°F | 67°F | 96°F 1989 | 59°F 1967 | 35% | 0% |
| Sep 3 | 85°F | 67°F | 95°F 1950 | 59°F 1967 | 35% | 0% |
| Sep 4 | 85°F | 67°F | 97°F 2020 | 52°F 1997 | 35% | 0% |
| Sep 5 | 84°F | 67°F | 97°F 1983 | 49°F 1997 | 34% | 0% |
| Sep 6 | 84°F | 67°F | 100°F 1954 | 51°F 1997 | 34% | 0% |
| Sep 7 | 84°F | 66°F | 97°F 1983 | 57°F 1982 | 34% | 0% |
| Sep 8 | 84°F | 66°F | 95°F 1985 | 54°F 1965 | 34% | 0% |
| Sep 9 | 84°F | 66°F | 95°F 1978 | 56°F 1998 | 33% | 0% |
| Sep 10 | 84°F | 66°F | 96°F 1990 | 52°F 1998 | 33% | 0% |
| Sep 11 | 83°F | 66°F | 99°F 1983 | 54°F 1998 | 33% | 0% |
| Sep 12 | 83°F | 65°F | 94°F 1983 | 56°F 2012 | 33% | 0% |
| Sep 13 | 83°F | 65°F | 92°F 1991 | 58°F 1962 | 32% | 0% |
| Sep 14 | 83°F | 65°F | 93°F 1952 | 50°F 1964 | 32% | 0% |
| Sep 15 | 82°F | 64°F | 93°F 1984 | 49°F 1964 | 32% | 0% |
| Sep 16 | 82°F | 64°F | 92°F 1956 | 54°F 1964 | 32% | 0% |
| Sep 17 | 82°F | 64°F | 94°F 1958 | 52°F 1963 | 32% | 0% |
| Sep 18 | 82°F | 64°F | 95°F 1958 | 54°F 2001 | 31% | 0% |
| Sep 19 | 82°F | 63°F | 93°F 1978 | 53°F 1990 | 31% | 0% |
| Sep 20 | 81°F | 63°F | 91°F 1965 | 52°F 1981 | 31% | 0% |
| Sep 21 | 81°F | 63°F | 93°F 1986 | 53°F 1962 | 31% | 0% |
| Sep 22 | 81°F | 62°F | 92°F 1957 | 50°F 2020 | 31% | 0% |
| Sep 23 | 81°F | 62°F | 90°F 1961 | 45°F 2020 | 30% | 0% |
| Sep 24 | 80°F | 62°F | 92°F 1986 | 47°F 1963 | 30% | 0% |
| Sep 25 | 80°F | 61°F | 95°F 1986 | 49°F 1990 | 30% | 0% |
| Sep 26 | 80°F | 61°F | 96°F 1986 | 49°F 1974 | 30% | 0% |
| Sep 27 | 80°F | 60°F | 96°F 1986 | 50°F 2001 | 30% | 0% |
| Sep 28 | 79°F | 60°F | 92°F 2017 | 49°F 1963 | 29% | 0% |
| Sep 29 | 79°F | 60°F | 95°F 2019 | 50°F 1962 | 29% | 0% |
| Sep 30 | 79°F | 59°F | 91°F 1986 | 46°F 1962 | 29% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (EDT).
- September 1
- sunrise 6:40 AM, sunset 7:34 PM
- September 30
- sunrise 7:01 AM, sunset 6:53 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00310576 (Bayboro 3 Sw), public domain. Records: NOAA GHCN-Daily, station USW00013754, 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.