Normal weather in September: Normal, Illinois: normal highs, lows, rain and records for September
Normal in September has a normal high of 79°F and a normal low of 53°F, a daily mean of 66°F, falling from 83°F on the 1st to 74°F by the 30th. Measurable precipitation falls on 8 days in a normal September, 3.22 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 26°C and low of 12°C, 82 mm of precipitation in September.
- NOAA stationNormal (4 mi NE)
- Station IDUSC00116200
- Location40.55°N 88.95°W
- Elevation790 ft (241 m)
- Population53,304
- Jan 33° 16°
- Feb 38° 19°
- Mar 50° 28°
- Apr 63° 38°
- May 74° 50°
- Jun 83° 60°
- Jul 86° 63°
- Aug 84° 61°
- Sep 79° 53°
- Oct 66° 42°
- Nov 50° 31°
- Dec 38° 21°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Normal in September?
The normal high is 79°F and the normal low 53°F, for a daily mean of 65.9°F. September is 6.7°F cooler than August and 12.2°F warmer than October. September is the 4th warmest month of the year in Normal and the 7th wettest. Across the month the normal high falls 9°F, from 83°F on September 1 to 74°F on September 30. From one year to the next September's mean temperature typically moves about 2.8°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 63°F and 69°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 28%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 83°F | 58°F | 28% | 20% |
| September 8 | 81°F | 56°F | 27% | 19% |
| September 15 | 79°F | 53°F | 27% | 19% |
| September 22 | 77°F | 51°F | 27% | 18% |
| September 30 | 74°F | 48°F | 27% | 19% |
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 | 83°F | 58°F | 28% | 20% | 13 h 10 min |
| September 2 | 83°F | 58°F | 27% | 20% | 13 h 10 min |
| September 3 | 82°F | 57°F | 27% | 20% | 13 h |
| September 4 | 82°F | 57°F | 27% | 20% | 13 h |
| September 5 | 82°F | 57°F | 27% | 19% | 13 h |
| September 6 | 82°F | 57°F | 27% | 19% | 13 h |
| September 7 | 82°F | 56°F | 27% | 19% | 12 h 50 min |
| September 8 | 81°F | 56°F | 27% | 19% | 12 h 50 min |
| September 9 | 81°F | 56°F | 27% | 19% | 12 h 50 min |
| September 10 | 81°F | 55°F | 27% | 19% | 12 h 40 min |
| September 11 | 81°F | 55°F | 27% | 19% | 12 h 40 min |
| September 12 | 80°F | 54°F | 27% | 19% | 12 h 40 min |
| September 13 | 80°F | 54°F | 27% | 19% | 12 h 40 min |
| September 14 | 80°F | 54°F | 27% | 19% | 12 h 30 min |
| September 15 | 79°F | 53°F | 27% | 19% | 12 h 30 min |
| September 16 | 79°F | 53°F | 27% | 18% | 12 h 30 min |
| September 17 | 79°F | 53°F | 27% | 18% | 12 h 30 min |
| September 18 | 78°F | 52°F | 27% | 18% | 12 h 20 min |
| September 19 | 78°F | 52°F | 27% | 18% | 12 h 20 min |
| September 20 | 78°F | 51°F | 27% | 18% | 12 h 20 min |
| September 21 | 77°F | 51°F | 27% | 18% | 12 h 20 min |
| September 22 | 77°F | 51°F | 27% | 18% | 12 h 10 min |
| September 23 | 77°F | 50°F | 27% | 18% | 12 h 10 min |
| September 24 | 76°F | 50°F | 27% | 18% | 12 h 10 min |
| September 25 | 76°F | 49°F | 27% | 18% | 12 h 10 min |
| September 26 | 75°F | 49°F | 27% | 18% | 12 h |
| September 27 | 75°F | 49°F | 27% | 18% | 12 h |
| September 28 | 74°F | 48°F | 27% | 19% | 12 h |
| September 29 | 74°F | 48°F | 27% | 19% | 11 h 50 min |
| September 30 | 74°F | 48°F | 27% | 19% | 11 h 50 min |
- Normal high
- 79°FSeptember average
- Normal low
- 53°FSeptember average
- Precipitation
- 3.22 inmonth total
- Days with precipitation
- 80.01 inch or more
- Days at 90°F or more
- 3
- Daylight
- 13 h 10 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 26
- Days at 80°F or more
- 14
- Sunshine
- 81%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00116200; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Normal in September?
On a given September day the chance of 0.01 inch or more is 27% on average, highest around September 1 (28%). In all, 3.22 in falls on 8 days of a normal September, 1 of them with an inch or more.
In a normal September in Normal, 3 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00116200.
What are the records for September in Normal?
The warmest September temperature on this station's record (since 1893) is 103°F, on September 5, 1899; the coldest is 22°F, on September 30, 1899. The wettest September brought 13.54 in (1961).
The September mean against the 1991-2020 normal of 65.9°F: 2021 68.9°F (+3.0), 2022 66.1°F (+0.2), 2023 66.6°F (+0.7), 2024 66.6°F (+0.7), 2025 67.9°F (+2.0), 2026 71.9°F (+6.0). 6 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 68.9°F | +3.0°F | 1.41 in |
| 2022 | 66.1°F | +0.2°F | 4.09 in |
| 2023 | 66.6°F | +0.7°F | 5.36 in |
| 2024 | 66.6°F | +0.7°F | 0.95 in |
| 2025 | 67.9°F | +2.0°F | 0.38 in |
| 2026 | 71.9°F | +6.0°F | 2.92 in |
Source: records: ACIS, station USC00116200; recent months: ACIS, station USC00116200. Records and recent months use complete months only.
How does September in Normal 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; Normal's is 79°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.