Brookfield weather in September: Brookfield, Wisconsin: normal highs, lows, rain and records for September
Brookfield in September has a normal high of 72°F and a normal low of 51°F, a daily mean of 62°F, falling from 77°F on the 1st to 67°F by the 30th. Measurable precipitation falls on 10 days in a normal September, 3.21 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 22°C and low of 11°C, 82 mm of precipitation in September.
- NOAA stationBrookfield Wastewater Treatment Plant
- Station IDUSC00471062
- Location43.05°N 88.18°W
- Elevation830 ft (253 m)
- From the center3 miles
- Population41,268
- Jan 28° 12°
- Feb 32° 15°
- Mar 42° 25°
- Apr 54° 35°
- May 67° 47°
- Jun 77° 56°
- Jul 81° 61°
- Aug 79° 60°
- Sep 72° 51°
- Oct 59° 40°
- Nov 45° 29°
- Dec 33° 19°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is Brookfield in September?
The normal high is 72°F and the normal low 51°F, for a daily mean of 61.8°F. September is 7.9°F cooler than August and 12.0°F warmer than October. September is the 4th warmest month of the year in Brookfield and the 6th wettest. Across the month the normal high falls 10°F, from 77°F on September 1 to 67°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 59°F and 65°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 38%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| September 1 | 77°F | 56°F | 35% | 24% |
| September 8 | 75°F | 54°F | 35% | 23% |
| September 15 | 73°F | 52°F | 35% | 22% |
| September 22 | 70°F | 49°F | 36% | 22% |
| September 30 | 67°F | 46°F | 38% | 22% |
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 | 77°F | 56°F | 35% | 24% | 13 h 10 min |
| September 2 | 76°F | 56°F | 35% | 24% | 13 h 10 min |
| September 3 | 76°F | 56°F | 35% | 24% | 13 h 10 min |
| September 4 | 76°F | 55°F | 35% | 24% | 13 h 10 min |
| September 5 | 76°F | 55°F | 35% | 24% | 13 h |
| September 6 | 75°F | 55°F | 35% | 24% | 13 h |
| September 7 | 75°F | 54°F | 35% | 24% | 13 h |
| September 8 | 75°F | 54°F | 35% | 23% | 12 h 50 min |
| September 9 | 75°F | 54°F | 35% | 23% | 12 h 50 min |
| September 10 | 74°F | 53°F | 35% | 23% | 12 h 50 min |
| September 11 | 74°F | 53°F | 35% | 23% | 12 h 50 min |
| September 12 | 74°F | 53°F | 35% | 23% | 12 h 40 min |
| September 13 | 73°F | 52°F | 35% | 23% | 12 h 40 min |
| September 14 | 73°F | 52°F | 35% | 23% | 12 h 40 min |
| September 15 | 73°F | 52°F | 35% | 22% | 12 h 30 min |
| September 16 | 72°F | 51°F | 35% | 22% | 12 h 30 min |
| September 17 | 72°F | 51°F | 35% | 22% | 12 h 30 min |
| September 18 | 72°F | 50°F | 35% | 22% | 12 h 30 min |
| September 19 | 71°F | 50°F | 35% | 22% | 12 h 20 min |
| September 20 | 71°F | 50°F | 36% | 22% | 12 h 20 min |
| September 21 | 71°F | 49°F | 36% | 22% | 12 h 20 min |
| September 22 | 70°F | 49°F | 36% | 22% | 12 h 10 min |
| September 23 | 70°F | 49°F | 36% | 22% | 12 h 10 min |
| September 24 | 69°F | 48°F | 36% | 22% | 12 h 10 min |
| September 25 | 69°F | 48°F | 36% | 21% | 12 h 10 min |
| September 26 | 69°F | 48°F | 37% | 22% | 12 h |
| September 27 | 68°F | 47°F | 37% | 22% | 12 h |
| September 28 | 68°F | 47°F | 38% | 22% | 12 h |
| September 29 | 67°F | 46°F | 38% | 22% | 11 h 50 min |
| September 30 | 67°F | 46°F | 38% | 22% | 11 h 50 min |
- Normal high
- 72°FSeptember average
- Normal low
- 51°FSeptember average
- Precipitation
- 3.21 inmonth total
- Days with precipitation
- 100.01 inch or more
- Days at 90°F or more
- 1
- Daylight
- 13 h 10 min to 11 h 50 minSeptember 1 to September 30
- Days at 70°F or more
- 20
- Days at 80°F or more
- 7
- Sunshine
- 77%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USC00471062; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain in Brookfield in September?
On a given September day the chance of 0.01 inch or more is 36% on average, highest around September 30 (38%). In all, 3.21 in falls on 10 days of a normal September, 1 of them with an inch or more.
In a normal September in Brookfield, 1 days reach 90°F.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USC00471062.
What are the records for September in Brookfield?
The September mean against the 1991-2020 normal of 61.8°F: 2021 64.1°F (+2.3), 2022 64.2°F (+2.4), 2023 65.4°F (+3.6), 2025 63.7°F (+1.9), 2026 64.3°F (+2.5). 5 of 5 ran warmer than normal.
| September | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 64.1°F | +2.3°F | 1.80 in |
| 2022 | 64.2°F | +2.4°F | 8.85 in |
| 2023 | 65.4°F | +3.6°F | 4.01 in |
| 2025 | 63.7°F | +1.9°F | 3.49 in |
| 2026 | 64.3°F | +2.5°F | 5.02 in |
Source: recent months: ACIS, station USC00471062. Records and recent months use complete months only.
How does September in Brookfield 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; Brookfield's is 72°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.
Other months and places
- Brookfield in August79°F by day, 60°F at night
- Brookfield in October59°F by day, 40°F at night
- Brookfield through the yearEvery month, frost dates, records and recent years
- Wisconsin in SeptemberThe statewide normal and the warmest and coolest places
- West Allis: Wisconsin's warmest Septembernormal high 77°F