West Allis weather in September: West Allis, Wisconsin: normal highs, lows, rain and records for September
West Allis in September has a normal high of 77°F and a normal low of 54°F, a daily mean of 65°F, falling from 82°F on the 1st to 70°F by the 30th. Measurable precipitation falls on 9 days in a normal September, 3.69 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 25°C and low of 12°C, 94 mm of precipitation in September.
- NOAA stationWest Allis
- Station IDUSC00479046
- Location43.02°N 88.00°W
- Elevation723 ft (220 m)
- From the center2 miles
- Population59,784
- Jan 31° 15°
- Feb 34° 17°
- Mar 45° 27°
- Apr 57° 37°
- May 70° 48°
- Jun 80° 58°
- Jul 85° 63°
- Aug 83° 62°
- Sep 77° 54°
- Oct 62° 42°
- Nov 48° 30°
- Dec 36° 21°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is West Allis in September?
The normal high is 77°F and the normal low 54°F, for a daily mean of 65.4°F. September is 7.0°F cooler than August and 13.4°F warmer than October. September is the 4th warmest month of the year in West Allis and the 6th wettest. Across the month the normal high falls 12°F, from 82°F on September 1 to 70°F on September 30. From one year to the next September's mean temperature typically moves about 2.6°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 35%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 82°F | 60°F | 30% | 20% |
| September 8 | 80°F | 58°F | 29% | 20% |
| September 15 | 77°F | 55°F | 30% | 20% |
| September 22 | 74°F | 52°F | 32% | 20% |
| September 30 | 70°F | 48°F | 35% | 20% |
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 | 60°F | 30% | 20% | 13 h 10 min |
| September 2 | 81°F | 60°F | 29% | 20% | 13 h 10 min |
| September 3 | 81°F | 59°F | 29% | 20% | 13 h 10 min |
| September 4 | 81°F | 59°F | 29% | 20% | 13 h 10 min |
| September 5 | 81°F | 59°F | 29% | 20% | 13 h |
| September 6 | 80°F | 58°F | 29% | 20% | 13 h |
| September 7 | 80°F | 58°F | 29% | 20% | 13 h |
| September 8 | 80°F | 58°F | 29% | 20% | 12 h 50 min |
| September 9 | 79°F | 57°F | 29% | 20% | 12 h 50 min |
| September 10 | 79°F | 57°F | 29% | 20% | 12 h 50 min |
| September 11 | 79°F | 56°F | 29% | 20% | 12 h 50 min |
| September 12 | 78°F | 56°F | 30% | 20% | 12 h 40 min |
| September 13 | 78°F | 56°F | 30% | 20% | 12 h 40 min |
| September 14 | 78°F | 55°F | 30% | 20% | 12 h 40 min |
| September 15 | 77°F | 55°F | 30% | 20% | 12 h 30 min |
| September 16 | 77°F | 54°F | 30% | 20% | 12 h 30 min |
| September 17 | 76°F | 54°F | 30% | 20% | 12 h 30 min |
| September 18 | 76°F | 53°F | 31% | 20% | 12 h 30 min |
| September 19 | 75°F | 53°F | 31% | 20% | 12 h 20 min |
| September 20 | 75°F | 53°F | 31% | 20% | 12 h 20 min |
| September 21 | 75°F | 52°F | 31% | 20% | 12 h 20 min |
| September 22 | 74°F | 52°F | 32% | 20% | 12 h 10 min |
| September 23 | 74°F | 51°F | 32% | 20% | 12 h 10 min |
| September 24 | 73°F | 51°F | 32% | 20% | 12 h 10 min |
| September 25 | 72°F | 50°F | 33% | 20% | 12 h 10 min |
| September 26 | 72°F | 50°F | 33% | 20% | 12 h |
| September 27 | 71°F | 49°F | 33% | 20% | 12 h |
| September 28 | 71°F | 49°F | 34% | 20% | 12 h |
| September 29 | 70°F | 49°F | 34% | 20% | 11 h 50 min |
| September 30 | 70°F | 48°F | 35% | 20% | 11 h 50 min |
- Normal high
- 77°FSeptember average
- Normal low
- 54°FSeptember average
- Precipitation
- 3.69 inmonth total
- Days with precipitation
- 90.01 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
- 23
- Days at 80°F or more
- 12
- Sunshine
- 77%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00479046; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in West Allis in September?
On a given September day the chance of 0.01 inch or more is 31% on average, highest around September 30 (35%). In all, 3.69 in falls on 9 days of a normal September, 1 of them with an inch or more.
In a normal September in West Allis, 2 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00479046.
What are the records for September in West Allis?
The warmest September temperature on this station's record (since 1948) is 99°F, on September 3, 1964; the coldest is 32°F, on September 25, 2001. The wettest September brought 9.05 in (1986).
The September mean against the 1991-2020 normal of 65.4°F: 2023 67.0°F (+1.6), 2024 68.0°F (+2.6), 2025 66.3°F (+0.9), 2026 66.2°F (+0.8). 4 of 4 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2023 | 67.0°F | +1.6°F | 4.64 in |
| 2024 | 68.0°F | +2.6°F | 2.26 in |
| 2025 | 66.3°F | +0.9°F | 2.67 in |
| 2026 | 66.2°F | +0.8°F | 4.39 in |
Source: records: ACIS, station USC00479046; recent months: ACIS, station USC00479046. Records and recent months use complete months only.
How does September in West Allis compare across Wisconsin?
Across the 165 places PlainClimate covers in Wisconsin, September normal highs run from 64°F in Laona to 77°F in West Allis; West Allis's is 77°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.