Rockford Weather in September
Average highs run from 86°F on September 1 to 78°F on September 30, and lows from 65°F to 56°F. Normal precipitation for the month is 3.49 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
- 83°F
- Average low
- 61°F
- Precipitation
- 3.49 in
- Record high
- 103°FSep 5, 1954
- Record low
- 36°FSep 30, 1967
- Chance of a freeze
- 0%
- Days of 90°F or more
- 4.5
- Daylight
- 12 h 55 min to 11 h 51 min
- Cloud cover
- 52%
- Humidity
- 67%
- Dew point
- 57°F
- Wind
- 4.3 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 | 86°F | 65°F | 100°F 1951 | 50°F 1946 | 28% | 0% |
| Sep 2 | 86°F | 65°F | 98°F 1953 | 48°F 1987 | 28% | 0% |
| Sep 3 | 86°F | 65°F | 98°F 1925 | 50°F 1987 | 27% | 0% |
| Sep 4 | 86°F | 65°F | 101°F 1954 | 51°F 1952 | 27% | 0% |
| Sep 5 | 86°F | 64°F | 103°F 1954 | 50°F 2010 | 27% | 0% |
| Sep 6 | 85°F | 64°F | 101°F 1925 | 47°F 1984 | 27% | 0% |
| Sep 7 | 85°F | 64°F | 102°F 1925 | 47°F 1984 | 26% | 0% |
| Sep 8 | 85°F | 64°F | 96°F 1925 | 46°F 1984 | 26% | 0% |
| Sep 9 | 85°F | 63°F | 100°F 1925 | 46°F 1984 | 26% | 0% |
| Sep 10 | 84°F | 63°F | 97°F 2019 | 48°F 1924 | 26% | 0% |
| Sep 11 | 84°F | 63°F | 96°F 1925 | 47°F 1976 | 26% | 0% |
| Sep 12 | 84°F | 63°F | 94°F 1931 | 45°F 1940 | 26% | 0% |
| Sep 13 | 84°F | 62°F | 97°F 1998 | 47°F 1940 | 26% | 0% |
| Sep 14 | 83°F | 62°F | 96°F 1998 | 45°F 1985 | 25% | 0% |
| Sep 15 | 83°F | 62°F | 96°F 1927 | 41°F 1985 | 25% | 0% |
| Sep 16 | 83°F | 61°F | 96°F 1927 | 43°F 1985 | 25% | 0% |
| Sep 17 | 82°F | 61°F | 95°F 1927 | 45°F 1985 | 25% | 0% |
| Sep 18 | 82°F | 61°F | 98°F 1931 | 46°F 1985 | 26% | 0% |
| Sep 19 | 82°F | 60°F | 98°F 1925 | 43°F 1984 | 26% | 0% |
| Sep 20 | 81°F | 60°F | 97°F 1925 | 45°F 1918 | 26% | 0% |
| Sep 21 | 81°F | 59°F | 95°F 1931 | 42°F 1918 | 26% | 0% |
| Sep 22 | 81°F | 59°F | 96°F 1931 | 38°F 1983 | 26% | 0% |
| Sep 23 | 80°F | 59°F | 96°F 1931 | 40°F 1983 | 26% | 0% |
| Sep 24 | 80°F | 58°F | 93°F 2007 | 37°F 1983 | 26% | 0% |
| Sep 25 | 80°F | 58°F | 94°F 2016 | 40°F 1983 | 26% | 0% |
| Sep 26 | 79°F | 58°F | 89°F 1933 | 41°F 2001 | 26% | 0% |
| Sep 27 | 79°F | 57°F | 92°F 2019 | 42°F 1928 | 26% | 0% |
| Sep 28 | 79°F | 57°F | 93°F 1939 | 37°F 1985 | 26% | 0% |
| Sep 29 | 78°F | 56°F | 95°F 2019 | 37°F 1942 | 25% | 0% |
| Sep 30 | 78°F | 56°F | 95°F 2019 | 36°F 1967 | 25% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (EDT).
- September 1
- sunrise 7:08 AM, sunset 8:03 PM
- September 30
- sunrise 7:30 AM, sunset 7:21 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USW00013891 (Knoxville Mcghee Tyson AP), public domain. Records: NOAA GHCN-Daily, station USW00013891, 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.