Galesburg weather in September: Galesburg, Illinois: normal highs, lows, rain and records for September
Galesburg in September has a normal high of 76°F and a normal low of 55°F, a daily mean of 66°F, falling from 80°F on the 1st to 71°F by the 30th. Measurable precipitation falls on 7 days in a normal September, 3.85 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 25°C and low of 13°C, 98 mm of precipitation in September.
- NOAA stationGalesburg
- Station IDUSC00113320
- Location40.95°N 90.39°W
- Elevation761 ft (232 m)
- From the centerunder 1 mile
- Population29,289
- Jan 30° 14°
- Feb 35° 17°
- Mar 48° 28°
- Apr 61° 40°
- May 72° 52°
- Jun 81° 62°
- Jul 84° 65°
- Aug 82° 63°
- Sep 76° 55°
- Oct 63° 43°
- Nov 48° 30°
- Dec 35° 20°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Galesburg in September?
The normal high is 76°F and the normal low 55°F, for a daily mean of 65.5°F. September is 7.3°F cooler than August and 12.7°F warmer than October. September is the 4th warmest month of the year in Galesburg and the 5th wettest. Across the month the normal high falls 9°F, from 80°F on September 1 to 71°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 63°F and 68°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 26%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 80°F | 60°F | 26% | 19% |
| September 8 | 79°F | 58°F | 25% | 19% |
| September 15 | 77°F | 55°F | 25% | 18% |
| September 22 | 74°F | 52°F | 25% | 18% |
| September 30 | 71°F | 49°F | 25% | 17% |
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 | 80°F | 60°F | 26% | 19% | 13 h 10 min |
| September 2 | 80°F | 60°F | 25% | 19% | 13 h 10 min |
| September 3 | 80°F | 60°F | 25% | 19% | 13 h |
| September 4 | 80°F | 59°F | 25% | 19% | 13 h |
| September 5 | 80°F | 59°F | 25% | 19% | 13 h |
| September 6 | 79°F | 59°F | 25% | 19% | 13 h |
| September 7 | 79°F | 58°F | 25% | 19% | 12 h 50 min |
| September 8 | 79°F | 58°F | 25% | 19% | 12 h 50 min |
| September 9 | 79°F | 57°F | 25% | 19% | 12 h 50 min |
| September 10 | 78°F | 57°F | 25% | 18% | 12 h 50 min |
| September 11 | 78°F | 57°F | 25% | 18% | 12 h 40 min |
| September 12 | 78°F | 56°F | 25% | 18% | 12 h 40 min |
| September 13 | 77°F | 56°F | 25% | 18% | 12 h 40 min |
| September 14 | 77°F | 55°F | 25% | 18% | 12 h 30 min |
| September 15 | 77°F | 55°F | 25% | 18% | 12 h 30 min |
| September 16 | 76°F | 55°F | 25% | 18% | 12 h 30 min |
| September 17 | 76°F | 54°F | 25% | 18% | 12 h 30 min |
| September 18 | 76°F | 54°F | 25% | 18% | 12 h 20 min |
| September 19 | 75°F | 53°F | 25% | 18% | 12 h 20 min |
| September 20 | 75°F | 53°F | 25% | 18% | 12 h 20 min |
| September 21 | 75°F | 53°F | 25% | 18% | 12 h 20 min |
| September 22 | 74°F | 52°F | 25% | 18% | 12 h 10 min |
| September 23 | 74°F | 52°F | 25% | 18% | 12 h 10 min |
| September 24 | 73°F | 51°F | 25% | 17% | 12 h 10 min |
| September 25 | 73°F | 51°F | 25% | 17% | 12 h 10 min |
| September 26 | 73°F | 51°F | 25% | 17% | 12 h |
| September 27 | 72°F | 50°F | 25% | 17% | 12 h |
| September 28 | 72°F | 50°F | 25% | 17% | 12 h |
| September 29 | 71°F | 49°F | 25% | 17% | 11 h 50 min |
| September 30 | 71°F | 49°F | 25% | 17% | 11 h 50 min |
- Normal high
- 76°FSeptember average
- Normal low
- 55°FSeptember average
- Precipitation
- 3.85 inmonth total
- Days with precipitation
- 70.01 inch or more
- Days at 90°F or more
- 2
- Daylight
- 13 h 10 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 24
- Days at 80°F or more
- 12
- Sunshine
- 82%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00113320; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Galesburg in September?
On a given September day the chance of 0.01 inch or more is 25% on average, highest around September 1 (26%). In all, 3.85 in falls on 7 days of a normal September, 1 of them with an inch or more.
In a normal September in Galesburg, 2 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00113320.
What are the records for September in Galesburg?
The warmest September temperature on this station's record (since 1896) is 100°F, on September 5, 1899; the coldest is 19°F, on September 30, 1899. The wettest September brought 11.57 in (1970); the snowiest, 2.0 inches (1942).
The September mean against the 1991-2020 normal of 65.5°F: 2021 68.4°F (+2.9), 2022 66.7°F (+1.2), 2023 67.1°F (+1.6), 2024 68.2°F (+2.7), 2025 68.6°F (+3.1), 2026 70.6°F (+5.1). 6 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 68.4°F | +2.9°F | 2.77 in |
| 2022 | 66.7°F | +1.2°F | 2.06 in |
| 2023 | 67.1°F | +1.6°F | 3.49 in |
| 2024 | 68.2°F | +2.7°F | 1.01 in |
| 2025 | 68.6°F | +3.1°F | 0.87 in |
| 2026 | 70.6°F | +5.1°F | 2.86 in |
Source: records: ACIS, station USC00113320; recent months: ACIS, station USC00113320. Records and recent months use complete months only.
How does September in Galesburg 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; Galesburg's is 76°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.