McLean County Weather in September
Average highs run from 85°F on September 1 to 77°F on September 30, and lows from 64°F to 54°F. Normal precipitation for the month is 3.13 in over about 6 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
- 59°F
- Precipitation
- 3.13 in
- Record high
- 105°FSep 5, 1954
- Record low
- 33°FSep 30, 1949
- Chance of a freeze
- 0%
- Days of 90°F or more
- 5.1
- Daylight
- 12 h 59 min to 11 h 50 min
- Cloud cover
- 47%
- Humidity
- 68%
- Dew point
- 58°F
- Wind
- 6.5 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 | 64°F | 102°F 1953 | 46°F 1987 | 19% | 0% |
| Sep 2 | 85°F | 64°F | 101°F 1953 | 44°F 1949 | 19% | 0% |
| Sep 3 | 85°F | 63°F | 100°F 1954 | 45°F 1952 | 19% | 0% |
| Sep 4 | 85°F | 63°F | 101°F 1954 | 43°F 1952 | 19% | 0% |
| Sep 5 | 85°F | 63°F | 105°F 1954 | 46°F 1952 | 19% | 0% |
| Sep 6 | 84°F | 62°F | 102°F 1954 | 47°F 1953 | 19% | 0% |
| Sep 7 | 84°F | 62°F | 101°F 1990 | 43°F 1988 | 19% | 0% |
| Sep 8 | 84°F | 62°F | 98°F 1980 | 46°F 1956 | 19% | 0% |
| Sep 9 | 84°F | 61°F | 100°F 1980 | 43°F 1956 | 19% | 0% |
| Sep 10 | 84°F | 61°F | 97°F 1983 | 46°F 1956 | 19% | 0% |
| Sep 11 | 83°F | 61°F | 98°F 1983 | 43°F 1976 | 19% | 0% |
| Sep 12 | 83°F | 60°F | 96°F 1980 | 44°F 1968 | 19% | 0% |
| Sep 13 | 83°F | 60°F | 98°F 1991 | 42°F 1955 | 19% | 0% |
| Sep 14 | 82°F | 60°F | 96°F 1956 | 37°F 2014 | 19% | 0% |
| Sep 15 | 82°F | 59°F | 97°F 1954 | 41°F 2014 | 19% | 0% |
| Sep 16 | 82°F | 59°F | 96°F 1954 | 40°F 1966 | 20% | 0% |
| Sep 17 | 82°F | 59°F | 94°F 1983 | 38°F 2014 | 20% | 0% |
| Sep 18 | 81°F | 58°F | 98°F 1953 | 43°F 1956 | 20% | 0% |
| Sep 19 | 81°F | 58°F | 97°F 1954 | 43°F 1973 | 20% | 0% |
| Sep 20 | 81°F | 58°F | 98°F 2018 | 40°F 1956 | 20% | 0% |
| Sep 21 | 80°F | 57°F | 97°F 2022 | 37°F 1956 | 20% | 0% |
| Sep 22 | 80°F | 57°F | 97°F 2022 | 36°F 1983 | 20% | 0% |
| Sep 23 | 80°F | 56°F | 95°F 2010 | 36°F 1974 | 20% | 0% |
| Sep 24 | 79°F | 56°F | 95°F 2007 | 35°F 1995 | 21% | 0% |
| Sep 25 | 79°F | 56°F | 93°F 1998 | 35°F 1965 | 21% | 0% |
| Sep 26 | 79°F | 55°F | 94°F 1998 | 34°F 2001 | 21% | 0% |
| Sep 27 | 78°F | 55°F | 95°F 1998 | 35°F 1991 | 21% | 0% |
| Sep 28 | 78°F | 55°F | 95°F 1999 | 36°F 1993 | 21% | 0% |
| Sep 29 | 77°F | 54°F | 97°F 1953 | 36°F 1951 | 21% | 0% |
| Sep 30 | 77°F | 54°F | 95°F 1953 | 33°F 1949 | 21% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (CDT).
- September 1
- sunrise 6:19 AM, sunset 7:18 PM
- September 30
- sunrise 6:44 AM, sunset 6:34 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00151227 (Calhoun Lock 2), public domain. Records: NOAA GHCN-Daily, station USC00155067, 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.