Whitefish Bay, United States — Weather in September 2026

Monthly climate averages for Whitefish Bay, United States. Based on 10-year ERA5 reanalysis data.

Dfb Warm-Summer Continental
8.9 /10
Excellent

September is an excellent month in Whitefish Bay

Climate Overview

Whitefish Bay, United States in September has warm conditions, with highs averaging 21.2°C (70°F). Rain falls on about 10 days this month.

This month falls at the beginning of Autumn.

Daily highs in September gradually drop from around 23°C (73°F) at the start to 19°C (66°F) by month's end.

September sees fairly even rainfall, totalling about 85 mm across the month.

Expect around 10.0h of sunshine at the start of September, decreasing to 8.8h by the end.

The warmest days tend to fall around the 1th, averaging 22.8°C (73°F).

Compared to August, this month is about 3°C cooler with 1 more rainy days. Temperatures begin dropping heading into October.

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Monthly September Averages

Temperature
21°C / 17°C
Feels Like
22°C / 16°C
Rain
10 days · 85 mm
Sunshine
9.4h / day
Humidity
75% — Humid
Wind
20 km/h
Wind Direction
SSE (162°)
Gusts
37 km/h
Daylight
12.5 h
Cloud Cover
49%
Clear Sky Days
7.1
UV Index
5.2 — High
Dew Point
15°C — Comfortable
Moon Phase
Waxing Crescent · 11%

Climate Charts

Daily averages based on historical data (2016–2025)

Daily Temperature

28°C 25°C 22°C 19°C 16°C 13°C 10°C 151015202530
High Low

Daily Precipitation

0 mm 2 mm 4 mm 6 mm 8 mm 151015202530
Rainfall

Daily Sunshine

0h 3h 6h 9h 12h 151015202530
Sunshine

Daily Wind Speed

0 6 12 18 24 30 151015202530
Wind Speed
Sun Position
Sunrise 06:31
Daylight 12.5h
Sunset 19:01

What to Expect

Daytime temperatures around 21°C (70°F) are ideal for full-day outdoor exploration.

Rain usually comes in shorter passing showers rather than all-day rain.

1 of the last 5 yearly records were warmer than this month's long-run average.

Compare Months

January
Poor
Temp
-1°C / -6°C
Feels Like
-6°C / -11°C
Rain
8days (57 mm) Wet
Sun
5.2h Fair
Humidity
76% Humid
UV
2 Low
Snow Days
11days
View Details
February
Poor
Temp
1°C / -5°C
Feels Like
-4°C / -11°C
Rain
7days (46 mm) Good
Sun
6.9h Fair
Humidity
73% Muggy
UV
3.1 Moderate
Snow Days
9days
View Details
March
Poor
Temp
4°C / 0°C
Feels Like
0°C / -6°C
Rain
10days (85 mm) Wet
Sun
7.8h Good
Humidity
73% Muggy
UV
4.2 Moderate
Snow Days
7days
View Details
April
Poor
Temp
8°C / 3°C
Feels Like
5°C / -1°C
Rain
13days (101 mm) Wet
Sun
9h Good
Humidity
74% Muggy
UV
5.3 High
Snow Days
4days
View Details
May
Fair
Temp
13°C / 9°C
Feels Like
12°C / 5°C
Rain
12days (103 mm) Wet
Sun
10.2h Excellent
Humidity
78% Humid
UV
6.2 High
View Details
June best
Excellent
Temp
20°C / 15°C
Feels Like
20°C / 14°C
Rain
11days (83 mm) Wet
Sun
11.8h Excellent
Humidity
77% Humid
UV
6.8 High
View Details
July best
Excellent
Temp
24°C / 19°C
Feels Like
26°C / 20°C
Rain
10days (84 mm) Wet
Sun
12.4h Excellent
Humidity
78% Humid
UV
7 High
View Details
August best
Excellent
Temp
24°C / 20°C
Feels Like
26°C / 20°C
Rain
9days (76 mm) Wet
Sun
11.3h Excellent
Humidity
77% Humid
UV
6.3 High
View Details
September best
Excellent
Temp
21°C / 17°C
Feels Like
22°C / 16°C
Rain
10days (85 mm) Wet
Sun
9.4h Good
Humidity
75% Muggy
UV
5.2 High
View Details
October
Fair
Temp
15°C / 10°C
Feels Like
13°C / 7°C
Rain
11days (93 mm) Wet
Sun
7.2h Good
Humidity
71% Muggy
UV
3.6 Moderate
Snow Days
1days
View Details
November
Poor
Temp
8°C / 3°C
Feels Like
4°C / -2°C
Rain
8days (53 mm) Wet
Sun
6.1h Fair
Humidity
70% Muggy
UV
2.3 Moderate
Snow Days
4days
View Details
December
Poor
Temp
2°C / -2°C
Feels Like
-3°C / -8°C
Rain
8days (52 mm) Wet
Sun
4.9h Fair
Humidity
74% Muggy
UV
1.7 Low
Snow Days
9days
View Details
Month Temp Feels Like Rain Sun Humidity UV Status
January -1°C / -6°C -6°C / -11°C 8days (57 mm) Wet 5.2h Fair 76% Humid 2 Low Poor View Details
February 1°C / -5°C -4°C / -11°C 7days (46 mm) Good 6.9h Fair 73% Muggy 3.1 Moderate Poor View Details
March 4°C / 0°C 0°C / -6°C 10days (85 mm) Wet 7.8h Good 73% Muggy 4.2 Moderate Poor View Details
April 8°C / 3°C 5°C / -1°C 13days (101 mm) Wet 9h Good 74% Muggy 5.3 High Poor View Details
May 13°C / 9°C 12°C / 5°C 12days (103 mm) Wet 10.2h Excellent 78% Humid 6.2 High Fair View Details
June best 20°C / 15°C 20°C / 14°C 11days (83 mm) Wet 11.8h Excellent 77% Humid 6.8 High Excellent View Details
July best 24°C / 19°C 26°C / 20°C 10days (84 mm) Wet 12.4h Excellent 78% Humid 7 High Excellent View Details
August best 24°C / 20°C 26°C / 20°C 9days (76 mm) Wet 11.3h Excellent 77% Humid 6.3 High Excellent View Details
September best 21°C / 17°C 22°C / 16°C 10days (85 mm) Wet 9.4h Good 75% Muggy 5.2 High Excellent View Details
October 15°C / 10°C 13°C / 7°C 11days (93 mm) Wet 7.2h Good 71% Muggy 3.6 Moderate Fair View Details
November 8°C / 3°C 4°C / -2°C 8days (53 mm) Wet 6.1h Fair 70% Muggy 2.3 Moderate Poor View Details
December 2°C / -2°C -3°C / -8°C 8days (52 mm) Wet 4.9h Fair 74% Muggy 1.7 Low Poor View Details

What to Wear

Dress in layers — a mix of long sleeves, light sweaters, and a versatile jacket works best for changeable conditions.

A waterproof jacket or compact umbrella is recommended for occasional showers.

Packing List

UmbrellaWaterproof jacketSunscreen (SPF 30+)SunglassesComfortable walking shoes

Frequently Asked Questions

September is typically excellent for visiting Whitefish Bay, with average highs of 21°C (70°F) and around 10 rainy days. Whitefish Bay, United States in September has warm conditions, with highs averaging 21.2°C (70°F). Rain falls on about 1
Whitefish Bay typically sees around 10 rainy days in September with 85 mm (3.3 in) of total rainfall. An umbrella should suffice.
Evenings in Whitefish Bay during September are mild at 17°C (62°F). A light cardigan is usually enough.
With highs of 21°C (70°F) and lows of 17°C (62°F) in September, we recommend: Umbrella, Waterproof jacket, Sunscreen (SPF 30+), Sunglasses, Comfortable walking shoes. Comfortable walking shoes are essential.
Yes, September offers some of the best weather conditions in Whitefish Bay with comfortable temperatures and lower chances of rain.
The average UV index in Whitefish Bay during September is 5 (moderate). Sunscreen and sunglasses are recommended during midday hours.
Whitefish Bay gets approximately 13 hours of daylight per day in September, with around 9 hours of sunshine.
Snow is uncommon in Whitefish Bay during September based on 10-year climate averages.

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