Milwaukee weather in September

In September, Milwaukee sees average daytime highs of 71°F and overnight lows near 58°F, with 3.0 in of rain across 9.2 wet days and about 12.3 hours of daylight. It is the 4th-warmest and 7th-wettest month of the year here.

Highs ease over the month, from about 75°F in the first days to 66°F by the end. The sky is clear or mostly clear about 39% of the time in September, and the air most often feels dry.

Daylight stretches from about 13 hours at the start of September to 11 h 36 min by month's end. Set against the rest of the year, September is Milwaukee's 1st-clearest and 9th-windiest month. For the whole year in context, see Milwaukee's year-round climate.

Daytime high
71°
4th warmest
Overnight low
58°
9th coldest
Rainfall
3.0 in
9.2 wet days
Daylight
12 h 18 min
5:37 AM – 5:55 PM
Cloud cover
52%
1st clearest
Wind
9 mph
9th windiest
Solar energy
4.31 kWh/m²
Travel score
6.7
out of 10

Milwaukee is city in and county seat of Milwaukee County, and largest city in State of Wisconsin, United States.

Density
2,248/km²
people per km²
Founded
1846

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs ease over the month, from about 75°F in the first days to 66°F by the end.

A typical September day in Milwaukee reaches about 71°F in the afternoon and slips back to 58°F overnight — a 13°F spread between the day's warmth and the night's chill. On most days the high lands between 61°F and 80°F. Set against its neighbours, September runs about 7°F cooler than August and about 12°F warmer than October.

40°50°60°70°80°151015202530
Avg high (°F)Avg low (°F)
17663
27563
37562
47562
57462
67461
77461
87360
97360
107360
117259
127259
137259
147158
157158
167158
177057
187057
196956
206956
216956
226855
236855
246754
256754
266653
276653
286653
296552
306552

How September really feels in Milwaukee

Once humidity and wind are folded in, September averages 0 days that feel above 90°F and 0 that feel at or below 32°F — the comfort signal a plain temperature reading hides.

Days feeling ≥ 90°F
0
heat index over the day's high
Days feeling ≤ 32°F
0
wind chill below the day's low

September sits comfortably in between — no days that feel dangerously hot or drop to a hard freeze once humidity and wind are folded in.

Milwaukee weather by month

How September compares with the rest of the year at a glance. September is the 4th-warmest and 7th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°F)Rainfall (inches)Wet daysSnow daysDaylight (hours)Travel score
Jan29° / 17°2.08.96.89.20.0
Feb31° / 19°1.975.510.20.0
Mar40° / 28°2.49.54.111.60.2
Apr50° / 38°4.111.91.713.12.2
May62° / 48°3.611.6014.44.9
Jun73° / 60°3.510.8015.16.6
Jul79° / 66°3.210.1014.86.7
Aug77° / 65°3.610.7013.86.8
Sep71° / 58°3.09.2012.36.7
Oct58° / 46°3.19.10.210.84.4
Nov45° / 34°2.48.61.79.51.0
Dec34° / 24°2.28.55.48.90.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 39% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 17% of September, with mostly cloudy or overcast conditions the remaining 45%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15941
25941
36040
46040
56040
66040
76040
85941
95842
105842
115743
125743
135644
145644
155545
165545
175545
185446
195446
205347
215347
225347
235248
245248
255248
265149
275149
285149
295050
305149

Chance of precipitation in September

Any precipitation

Milwaukee gets around 3.0 in of rain over 9.2 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 31% and peaks near 32% on the wettest days.

0%10%20%30%40%151015202530
Rain chance (%)
131
231
330
430
530
630
730
830
930
1030
1131
1231
1332
1432
1532
1632
1732
1832
1932
2032
2132
2232
2332
2432
2532
2632
2732
2831
2931
3030

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the dry band about 51% of days. Sticky, muggy-or-worse air turns up on roughly 12% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
1242623215
2262622205
3282622195
4302621184
5312621184
6332621173
7352620163
8372520152
9392520152
10402420142
11422419132
12442319121
13452319121
14472219111
15492218101
1650221891
1752211791
1855211680
1956211670
2058201570
2160201460
2263191350
2365181250
2467171150
2569171040
2670161040
277215940
287514830
297514830
307713730

Wind in September

Winds average 9 mph in September.

Across September, daily wind ranges from about 8 mph on the calmest days to 10 mph at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (mph)Feels
18light breeze
29light breeze
39light breeze
49light breeze
59light breeze
69light breeze
79light breeze
89light breeze
99light breeze
109light breeze
119light breeze
129light breeze
139light breeze
149light breeze
159light breeze
169light breeze
179light breeze
189light breeze
199light breeze
2010light breeze
2110light breeze
2210light breeze
2310light breeze
2410light breeze
2510light breeze
2610light breeze
2710light breeze
2810light breeze
2910light breeze
3010light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 13 hours at the start of September to 11 h 36 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 84 minutes over September. Sunrise moves from 5:20 AM to 5:53 AM, and sunset from 6:22 PM to 5:29 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
113.05:206:22
213.05:226:20
312.95:236:19
412.95:246:17
512.85:256:15
612.85:266:13
712.75:276:11
812.75:286:10
912.65:296:08
1012.65:316:06
1112.55:326:04
1212.55:336:02
1312.45:346:00
1412.45:355:58
1512.35:365:56
1612.35:375:55
1712.25:385:53
1812.25:405:51
1912.15:415:49
2012.15:425:47
2112.05:435:45
2212.05:445:43
2311.95:455:41
2411.95:465:40
2511.85:485:38
2611.85:495:36
2711.75:505:34
2811.75:515:32
2911.65:525:30
3011.65:535:29

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.31 kWh/m².

For context, solar energy here swings from a low near 1.49 kWh/m² to a high of 6.43 kWh/m² in June across the year — September's 4.31 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.9Bright
24.9Bright
34.8Bright
44.8Bright
54.8Bright
64.7Bright
74.7Bright
84.6Bright
94.6Bright
104.5Bright
114.5Bright
124.4Bright
134.4Bright
144.3Bright
154.3Bright
164.3Bright
174.2Bright
184.2Bright
194.1Bright
204.1Bright
214.0Bright
224.0Bright
234.0Moderate
243.9Moderate
253.9Moderate
263.9Moderate
273.8Moderate
283.8Moderate
293.7Moderate
303.7Moderate
Planning a trip in September

Is September a good time to visit Milwaukee?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

6.7
Sightseeing
2nd-best month of the year
4.3
Beach & pool
4th-best month of the year

September is a reasonable time to visit Milwaukee for sightseeing.

What to pack for Milwaukee in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Milwaukee sees daytime highs around 71°F and nights near 58°F. Worth packing: rain gear. About 9 days see rain.

rain gear

Sea temperature near Milwaukee in September

The nearest coast averages about 66°F in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in August at about 70°F and coldest in March near 36°F.

It's comfortable for a long swim from Jul 29 to Aug 30 — about 1.1 months when the water holds above 68°F.

30°40°50°60°70°JanFebMarAprMayJunJulAugSepOctNovDecbracingcoolrefreshingwarm
Sea temperature (°F)Comfort
Jan38Bracing
Feb36Bracing
Mar36Bracing
Apr38Bracing
May42Bracing
Jun54Bracing
Jul67Cool
Aug70Refreshing
Sep66Cool
Oct56Bracing
Nov46Bracing
Dec41Bracing

UV index in Milwaukee in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 5 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Milwaukee peaks around June 20 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 1 (low).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 8 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecLowModerateHighVery highHighModerateLowJun 20UV 9Jan 1UV 1
UV index (midday)Level
Jan1Low
Feb2Moderate
Mar4Moderate
Apr6High
May8Very high
Jun9Very high
Jul8Very high
Aug7Very high
Sep5High
Oct3Moderate
Nov2Low
Dec1Low

Air quality in Milwaukee in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Milwaukee is worst in July — around 17 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (October, 9 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1017 µg/m³Oct 249 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb13Moderate
Mar15Moderate
Apr15Moderate
May16Moderate
Jun17Moderate
Jul17Moderate
Aug16Moderate
Sep13Moderate
Oct9Good
Nov9Good
Dec10Good
Location & terrain

Where is Milwaukee?

Milwaukee sits at 43.0°N, 87.9°W, 617 ft above sea level, in United States. The nearest listed city is Wauwatosa, 5.0 mi away.

Topography around Milwaukee

How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Milwaukee.

Within 2 miles, the terrain around Milwaukee has only modest variations in elevation — a maximum elevation change of 190 ft around an average of 617 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 469 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 846 ft.

The land around Milwaukee is covered by artificial surfaces (59%) and water (28%) within 2 miles, water (40%), artificial surfaces (30%) and trees (21%) within 10 miles, and water (46%) and cropland (21%) within 50 miles.

2 miles
190 ft
10 miles
469 ft
50 miles
846 ft
treesgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Wauwatosa 5.0 mi · West Allis 5.6 mi · Cudahy 6.2 mi · Greenfield 7.5 mi · South Milwaukee 9.3 mi · Brookfield 9.9 mi · Oak Creek 11 mi · New Berlin 11 mi

United States travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 100% of US
price level, 2025
GDP per capita
$90,027
2025
Happiness
6.8 / 10
World Happiness, 2025
Safe drinking water
98%
of population, 2024
Homicide rate
5.8
per 100k, 2023
Road deaths
12.7
per 100k/yr, 2019
Income group
High
World Bank
Religion
Protestant 47%unaffiliated 23%Roman Catholic 21%Jewish 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Milwaukee (43.0389°, -87.9065°, elevation 617 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).