Collinsville Weather in September
Average highs run from 90°F on September 1 to 80°F on September 30, and lows from 68°F to 57°F. Normal precipitation for the month is 3.85 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
- 85°F
- Average low
- 63°F
- Precipitation
- 3.85 in
- Record high
- 109°FSep 2, 1939
- Record low
- 35°FSep 27, 1942
- Chance of a freeze
- 0%
- Days of 90°F or more
- 9.0
- Daylight
- 12 h 56 min to 11 h 50 min
- Cloud cover
- 44%
- Humidity
- 66%
- Dew point
- 59°F
- Wind
- 9.4 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 | 90°F | 68°F | 108°F 2000 | 48°F 1967 | 25% | 0% |
| Sep 2 | 89°F | 68°F | 109°F 1939 | 51°F 1974 | 25% | 0% |
| Sep 3 | 89°F | 67°F | 109°F 1939 | 47°F 1974 | 25% | 0% |
| Sep 4 | 89°F | 67°F | 107°F 1998 | 46°F 1974 | 25% | 0% |
| Sep 5 | 88°F | 67°F | 105°F 1998 | 49°F 1974 | 25% | 0% |
| Sep 6 | 88°F | 66°F | 105°F 2026 | 48°F 2011 | 25% | 0% |
| Sep 7 | 88°F | 66°F | 105°F 1998 | 49°F 2011 | 25% | 0% |
| Sep 8 | 88°F | 66°F | 103°F 2026 | 50°F 1956 | 25% | 0% |
| Sep 9 | 87°F | 65°F | 103°F 2026 | 51°F 1943 | 25% | 0% |
| Sep 10 | 87°F | 65°F | 99°F 1939 | 48°F 1962 | 25% | 0% |
| Sep 11 | 87°F | 65°F | 102°F 2000 | 45°F 1940 | 25% | 0% |
| Sep 12 | 86°F | 64°F | 100°F 1956 | 48°F 1940 | 26% | 0% |
| Sep 13 | 86°F | 64°F | 103°F 1965 | 49°F 1960 | 26% | 0% |
| Sep 14 | 85°F | 64°F | 103°F 1965 | 46°F 1961 | 26% | 0% |
| Sep 15 | 85°F | 63°F | 103°F 1956 | 42°F 1993 | 26% | 0% |
| Sep 16 | 85°F | 63°F | 103°F 1956 | 44°F 1993 | 26% | 0% |
| Sep 17 | 84°F | 62°F | 99°F 2026 | 44°F 1981 | 26% | 0% |
| Sep 18 | 84°F | 62°F | 100°F 1952 | 42°F 1981 | 26% | 0% |
| Sep 19 | 84°F | 62°F | 100°F 1954 | 45°F 1991 | 26% | 0% |
| Sep 20 | 83°F | 61°F | 102°F 1954 | 42°F 1971 | 26% | 0% |
| Sep 21 | 83°F | 61°F | 99°F 2022 | 42°F 1983 | 25% | 0% |
| Sep 22 | 83°F | 60°F | 98°F 1956 | 37°F 1995 | 25% | 0% |
| Sep 23 | 82°F | 60°F | 96°F 1939 | 37°F 1995 | 25% | 0% |
| Sep 24 | 82°F | 60°F | 98°F 1939 | 37°F 1989 | 25% | 0% |
| Sep 25 | 82°F | 59°F | 99°F 1939 | 42°F 2001 | 25% | 0% |
| Sep 26 | 81°F | 59°F | 94°F 2021 | 38°F 1940 | 25% | 0% |
| Sep 27 | 81°F | 58°F | 96°F 1953 | 35°F 1942 | 25% | 0% |
| Sep 28 | 80°F | 58°F | 102°F 1953 | 39°F 1967 | 25% | 0% |
| Sep 29 | 80°F | 58°F | 98°F 1953 | 40°F 1949 | 25% | 0% |
| Sep 30 | 80°F | 57°F | 99°F 1979 | 35°F 1984 | 25% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- September 1
- sunrise 6:55 AM, sunset 7:51 PM
- September 30
- sunrise 7:18 AM, sunset 7:08 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00013968 (Tulsa Intl AP), public domain. Records: NOAA GHCN-Daily, station USW00013968, 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.