Peoria weather in September: Peoria, Illinois: normal highs, lows, rain and records for September
Peoria in September has a normal high of 78°F and a normal low of 56°F, a daily mean of 67°F, falling from 83°F on the 1st to 73°F by the 30th. Measurable precipitation falls on 8 days in a normal September, 3.48 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 26°C and low of 13°C, 88 mm of precipitation in September.
- NOAA stationGeneral Wayne A. Downing International Airport
- Station IDUSW00014842
- Location40.67°N 89.68°W
- Elevation650 ft (198 m)
- From the center7 miles
- Population111,696
- Jan 34° 18°
- Feb 39° 21°
- Mar 51° 32°
- Apr 64° 42°
- May 74° 53°
- Jun 83° 62°
- Jul 86° 66°
- Aug 85° 64°
- Sep 78° 56°
- Oct 65° 44°
- Nov 51° 33°
- Dec 39° 23°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Peoria in September?
The normal high is 78°F and the normal low 56°F, for a daily mean of 67.4°F. September is 7.1°F cooler than August and 12.5°F warmer than October. September is the 4th warmest month of the year in Peoria and the 5th wettest. Across the month the normal high falls 10°F, from 83°F on September 1 to 73°F on September 30. From one year to the next September's mean temperature typically moves about 3.1°F either way (NOAA's standard deviation), so roughly two Septembers in three average between 64°F and 71°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 27%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 83°F | 62°F | 27% | 19% |
| September 8 | 81°F | 59°F | 26% | 18% |
| September 15 | 79°F | 57°F | 26% | 17% |
| September 22 | 76°F | 54°F | 27% | 17% |
| September 30 | 73°F | 51°F | 27% | 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 | 83°F | 62°F | 27% | 19% | 13 h 10 min |
| September 2 | 83°F | 61°F | 26% | 18% | 13 h 10 min |
| September 3 | 82°F | 61°F | 26% | 18% | 13 h |
| September 4 | 82°F | 61°F | 26% | 18% | 13 h |
| September 5 | 82°F | 60°F | 26% | 18% | 13 h |
| September 6 | 82°F | 60°F | 26% | 18% | 13 h |
| September 7 | 81°F | 60°F | 26% | 18% | 12 h 50 min |
| September 8 | 81°F | 59°F | 26% | 18% | 12 h 50 min |
| September 9 | 81°F | 59°F | 26% | 18% | 12 h 50 min |
| September 10 | 81°F | 59°F | 26% | 18% | 12 h 50 min |
| September 11 | 80°F | 58°F | 26% | 17% | 12 h 40 min |
| September 12 | 80°F | 58°F | 26% | 17% | 12 h 40 min |
| September 13 | 80°F | 57°F | 26% | 17% | 12 h 40 min |
| September 14 | 79°F | 57°F | 26% | 17% | 12 h 30 min |
| September 15 | 79°F | 57°F | 26% | 17% | 12 h 30 min |
| September 16 | 79°F | 56°F | 26% | 17% | 12 h 30 min |
| September 17 | 78°F | 56°F | 26% | 17% | 12 h 30 min |
| September 18 | 78°F | 55°F | 26% | 17% | 12 h 20 min |
| September 19 | 78°F | 55°F | 26% | 17% | 12 h 20 min |
| September 20 | 77°F | 55°F | 26% | 17% | 12 h 20 min |
| September 21 | 77°F | 54°F | 27% | 17% | 12 h 20 min |
| September 22 | 76°F | 54°F | 27% | 17% | 12 h 10 min |
| September 23 | 76°F | 53°F | 27% | 17% | 12 h 10 min |
| September 24 | 76°F | 53°F | 27% | 17% | 12 h 10 min |
| September 25 | 75°F | 53°F | 27% | 17% | 12 h 10 min |
| September 26 | 75°F | 52°F | 27% | 17% | 12 h |
| September 27 | 74°F | 52°F | 27% | 17% | 12 h |
| September 28 | 74°F | 51°F | 27% | 17% | 12 h |
| September 29 | 73°F | 51°F | 27% | 17% | 11 h 50 min |
| September 30 | 73°F | 51°F | 27% | 17% | 11 h 50 min |
- Normal high
- 78°FSeptember average
- Normal low
- 56°FSeptember average
- Precipitation
- 3.48 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
- 25
- Days at 80°F or more
- 13
- Sunshine
- 81%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00014842; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Peoria in September?
On a given September day the chance of 0.01 inch or more is 26% on average, highest around September 30 (27%). In all, 3.48 in falls on 8 days of a normal September, 1 of them with an inch or more.
In a normal September in Peoria, 3 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00014842.
How humid and windy is Peoria in September?
At 3 p.m. the normal temperature is 71°F with 47% relative humidity and a dew point of 49°F; at 6 a.m. it is 53°F with 86% humidity. The wind averages 7.0 mph, most often from the west-southwest in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 53°F | 48°F | 86% | 5.3 mph | 64% |
| 9 a.m. | 61°F | 51°F | 70% | 8.1 mph | 64% |
| noon | 68°F | 50°F | 52% | 9.5 mph | 61% |
| 3 p.m. | 71°F | 49°F | 47% | 9.4 mph | 60% |
| 6 p.m. | 64°F | 50°F | 60% | 5.8 mph | 67% |
| 9 p.m. | 59°F | 50°F | 71% | 6.3 mph | 70% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00014842. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for September in Peoria?
The warmest September temperature on Peoria's official record (since 1883) is 104°F, on September 5, 1899; the coldest is 26°F, on September 30, 1899. The wettest September brought 13.09 in (1961); the snowiest, 1.0 inches (1942).
The September mean against the 1991-2020 normal of 67.4°F: 2021 71.3°F (+3.9), 2022 68.1°F (+0.7), 2023 70.1°F (+2.7), 2024 70.0°F (+2.6), 2025 70.0°F (+2.6), 2026 71.8°F (+4.4). 6 of 6 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 71.3°F | +3.9°F | 1.09 in |
| 2022 | 68.1°F | +0.7°F | 0.79 in |
| 2023 | 70.1°F | +2.7°F | 2.05 in |
| 2024 | 70.0°F | +2.6°F | 0.72 in |
| 2025 | 70.0°F | +2.6°F | 0.09 in |
| 2026 | 71.8°F | +4.4°F | 3.09 in |
Source: records: ACIS, NWS threaded record PIAthr; recent months: ACIS, station USW00014842. Records and recent months use complete months only.
How does September in Peoria 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; Peoria's is 78°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.