Champaign weather in September: Champaign, Illinois: normal highs, lows, rain and records for September
Champaign in September has a normal high of 79°F and a normal low of 55°F, a daily mean of 67°F, falling from 82°F on the 1st to 75°F by the 30th. Measurable precipitation falls on 9 days in a normal September, 3.05 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 26°C and low of 13°C, 77 mm of precipitation in September.
- NOAA stationChampaign Willard Airport
- Station IDUSW00094870
- Location40.04°N 88.28°W
- Elevation754 ft (230 m)
- From the center5 miles
- Population91,961
- Jan 34° 18°
- Feb 39° 22°
- Mar 52° 31°
- Apr 65° 41°
- May 76° 52°
- Jun 84° 62°
- Jul 85° 64°
- Aug 84° 62°
- Sep 79° 55°
- Oct 67° 43°
- Nov 52° 32°
- Dec 39° 24°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Champaign in September?
The normal high is 79°F and the normal low 55°F, for a daily mean of 67.0°F. September is 5.8°F cooler than August and 12.0°F warmer than October. September is the 4th warmest month of the year in Champaign and the 6th wettest. Across the month the normal high falls 7°F, from 82°F on September 1 to 75°F on September 30. From one year to the next September's mean temperature typically moves about 2.9°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 64°F and 70°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 32%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 82°F | 59°F | 32% | 17% |
| September 8 | 82°F | 57°F | 31% | 17% |
| September 15 | 80°F | 55°F | 30% | 16% |
| September 22 | 78°F | 52°F | 30% | 16% |
| September 30 | 75°F | 49°F | 31% | 16% |
Every day of September: normal high, low and chance of precipitation (warmest afternoon September 1, coldest night September 30)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| September 1 | 82°F | 59°F | 32% | 17% | 13 h 10 min |
| September 2 | 82°F | 59°F | 31% | 17% | 13 h |
| September 3 | 82°F | 59°F | 31% | 17% | 13 h |
| September 4 | 82°F | 58°F | 31% | 17% | 13 h |
| September 5 | 82°F | 58°F | 31% | 17% | 13 h |
| September 6 | 82°F | 58°F | 31% | 17% | 12 h 50 min |
| September 7 | 82°F | 58°F | 31% | 17% | 12 h 50 min |
| September 8 | 82°F | 57°F | 31% | 17% | 12 h 50 min |
| September 9 | 81°F | 57°F | 31% | 16% | 12 h 50 min |
| September 10 | 81°F | 57°F | 31% | 16% | 12 h 40 min |
| September 11 | 81°F | 56°F | 31% | 16% | 12 h 40 min |
| September 12 | 81°F | 56°F | 31% | 16% | 12 h 40 min |
| September 13 | 81°F | 56°F | 31% | 16% | 12 h 40 min |
| September 14 | 80°F | 55°F | 30% | 16% | 12 h 30 min |
| September 15 | 80°F | 55°F | 30% | 16% | 12 h 30 min |
| September 16 | 80°F | 55°F | 30% | 16% | 12 h 30 min |
| September 17 | 79°F | 54°F | 30% | 16% | 12 h 30 min |
| September 18 | 79°F | 54°F | 30% | 16% | 12 h 20 min |
| September 19 | 79°F | 53°F | 30% | 16% | 12 h 20 min |
| September 20 | 79°F | 53°F | 30% | 16% | 12 h 20 min |
| September 21 | 78°F | 53°F | 30% | 16% | 12 h 20 min |
| September 22 | 78°F | 52°F | 30% | 16% | 12 h 10 min |
| September 23 | 78°F | 52°F | 30% | 16% | 12 h 10 min |
| September 24 | 77°F | 52°F | 30% | 16% | 12 h 10 min |
| September 25 | 77°F | 51°F | 30% | 16% | 12 h 10 min |
| September 26 | 76°F | 51°F | 30% | 16% | 12 h |
| September 27 | 76°F | 50°F | 30% | 16% | 12 h |
| September 28 | 76°F | 50°F | 30% | 16% | 12 h |
| September 29 | 75°F | 50°F | 30% | 16% | 11 h 50 min |
| September 30 | 75°F | 49°F | 31% | 16% | 11 h 50 min |
- Normal high
- 79°FSeptember average
- Normal low
- 55°FSeptember average
- Precipitation
- 3.05 inmonth total
- Days with precipitation
- 90.01 inch or more
- Days at 90°F or more
- 4
- Daylight
- 13 h 10 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 27
- Days at 80°F or more
- 15
- Sunshine
- 81%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00094870; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Champaign in September?
On a given September day the chance of 0.01 inch or more is 31% on average, highest around September 1 (32%). In all, 3.05 in falls on 9 days of a normal September, 1 of them with an inch or more.
In a normal September in Champaign, 4 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00094870.
What are the records for September in Champaign?
The warmest September temperature on this station's record (since 1997) is 99°F, on September 1, 2011; the coldest is 33°F, on September 25, 2001. The wettest September brought 7.32 in (2008).
The September mean against the 1991-2020 normal of 67.0°F: 2021 70.2°F (+3.2), 2022 66.5°F (−0.5), 2023 68.7°F (+1.7), 2024 68.6°F (+1.6), 2025 69.9°F (+2.9), 2026 72.3°F (+5.3). 5 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 70.2°F | +3.2°F | 3.08 in |
| 2022 | 66.5°F | −0.5°F | 2.26 in |
| 2023 | 68.7°F | +1.7°F | 2.71 in |
| 2024 | 68.6°F | +1.6°F | 2.61 in |
| 2025 | 69.9°F | +2.9°F | 0.96 in |
| 2026 | 72.3°F | +5.3°F | 3.21 in |
Source: records: ACIS, station USW00094870; recent months: ACIS, station USW00094870. Records and recent months use complete months only.
How does September in Champaign compare across Illinois?
Across the 144 places PlainClimate covers in Illinois, September normal highs run from 72°F in Barrington to 84°F in Anna; Champaign's is 79°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.