Ann Arbor, MI Climate & Monthly Averages

Ann Arbor has a humid continental climate. July is the hottest month, averaging 82° by day; January is the coldest at 32°.

Michigan, United States 🇺🇸 · humid continental climate
Annual avg
50°
Hottest month
July
Coldest month
January
Rainy days / yr
130
Sunshine
8.2 h/day
Right now: 41° and patchy rain nearby - see live conditions

Ann Arbor's climate is a story of contrasts

A 26°C spread between its warmest and coolest months puts Ann Arbor among the more strongly seasonal places we cover. July averages 82°F (28°C) by day; January averages 32°F (0°C), with nights at 19°F (-7°C).

Warm end

July

82° by day 64° at night
Cold end

January

32° by day 19° at night

The two ends of the year

July is the warm end of the year, averaging 82°F (28°C) by day and 64°F (18°C) overnight. January bottoms out at 32°F (0°C) in daylight, 19°F (-7°C) after dark. The gridded 2015-2024 daily record for this location tops out at 94°F (34°C) and bottoms at -25°F (-32°C) - decade extremes, not all-time station records. The wettest month is July (3.6 inches (91 mm) across 12 days) and the driest November.

July is the brightest month at 12.2 hours of sun a day, against an annual average of 8.2 - duller than about 78% of the cities we track. Between the average July and the average January lie 26°C, a wider spread than roughly 88% of the cities we track.

More climate facts for Ann Arbor
  • Hottest month: July - highs near 82°F (28°C)
  • Coldest month: January - highs near 32°F (0°C)
  • Decade extremes (2015-2024): 94°F (34°C) high · -25°F (-32°C) low
  • Wettest month: July (12 rainy days) · Sunniest: July (12.2 h sun/day)
  • Climate type: humid continental
  • Annual swing: 26°C between the average warmest and coolest month · day to night: 9°C
  • Snow: about 19 days a year
  • Months with freezing average lows: 4
  • Average humidity: 71%

Four distinct parts of the year in Ann Arbor

Spring (March through May)

Spring in Ann Arbor is mild, with daytime highs averaging 57°F (14°C) and nights around 38°F (4°C); rain falls on around 36 of the 90 days, plus about 5 snowy days.

Summer (June through August)

Summer in Ann Arbor settles into easy warmth, with daytime highs averaging 80°F (27°C) and nights around 62°F (17°C); rain falls on around 34 of the 90 days. Daylight is generous - around 11.8 hours of sun a day.

Fall (September through November)

Fall in Ann Arbor is crisp but comfortable, with daytime highs averaging 61°F (16°C) and nights around 46°F (8°C); expect showers on roughly 30 days across the season, plus about 2 snowy days.

Winter (December through February)

Winter in Ann Arbor is frigid, with daytime highs averaging 36°F (2°C) and nights around 22°F (-6°C); expect showers on roughly 30 days across the season, plus about 12 snowy days. Wind sharpens cold like this considerably; pair the forecast winds with the wind speed converter to judge exposed conditions.

Ann Arbor temperature extremes in the 2015–2024 dataset

Highest daily value
94°
in June
Lowest daily value
-25°
in February
Annual precipitation
36.7"
Snowy days / yr
19

Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ. Need another precipitation unit? Use the rainfall converter.

Choosing a season in Ann Arbor

Best time to visit Ann Arbor

June to October is the sweet spot for Ann Arbor - these are the warmest and brightest weeks of the year. Expect 75°F (24°C) in the afternoon and around 11 days of rain in a typical month of it. For the same question asked the other way round, see where else is warm in June.

What to pack

Pack for Ann Arbor with light clothing for the warm months, a heavy insulated coat, hat and gloves for winter and a compact umbrella or rain shell. July nights average 64°F (18°C), so evenings rarely match the afternoons.

Monthly highs, lows and seasonal change

Monthly averages for Ann Arbor based on 2015–2024 weather data. Daylight is sunrise to sunset on the 15th; wet-day chance is the share of days with measurable rain.
MonthHighLow Rain daysPrecipitation SunshineDaylightWet-day chanceHumidity
January 32° 19° 10 2.5 in 4.4 h/day 9.4 h 33% 75%
February 36° 19° 9 2.5 in 6.5 h/day 10.5 h 32% 73%
March 46° 28° 10 3.2 in 7.5 h/day 11.8 h 33% 67%
April 56° 37° 13 3.4 in 8.6 h/day 13.3 h 44% 67%
May 69° 50° 12 3.6 in 10.1 h/day 14.6 h 40% 68%
June 78° 59° 12 3.5 in 12.0 h/day 15.3 h 39% 66%
July 82° 64° 12 3.6 in 12.2 h/day 15.0 h 37% 70%
August 80° 63° 11 3.5 in 11.2 h/day 13.9 h 36% 72%
September 74° 58° 9 2.9 in 9.4 h/day 12.4 h 30% 74%
October 61° 46° 11 3.4 in 7.1 h/day 11.0 h 36% 73%
November 47° 34° 9 2.3 in 5.8 h/day 9.7 h 31% 73%
December 39° 27° 10 2.5 in 4.1 h/day 9.1 h 34% 77%

Ann Arbor from the coldest month to the hottest

Each card shows the average high and low. The bar places that month between Ann Arbor's coldest night and warmest afternoon.

January

Coldest
32°19°
Rain
10 days
Sunshine
4.4 h
Daylight
9.4 h
Snow
5 days

February

36°19°
Rain
9 days
Sunshine
6.5 h
Daylight
10.5 h
Snow
4 days

March

46°28°
Rain
10 days
Sunshine
7.5 h
Daylight
11.8 h
Snow
3 days

April

56°37°
Rain
13 days
Sunshine
8.6 h
Daylight
13.3 h
Snow
2 days

May

69°50°
Rain
12 days
Sunshine
10.1 h
Daylight
14.6 h

June

78°59°
Rain
12 days
Sunshine
12.0 h
Daylight
15.3 h

July

HottestWettestSunniest
82°64°
Rain
12 days
Sunshine
12.2 h
Daylight
15.0 h

August

80°63°
Rain
11 days
Sunshine
11.2 h
Daylight
13.9 h

September

74°58°
Rain
9 days
Sunshine
9.4 h
Daylight
12.4 h

October

61°46°
Rain
11 days
Sunshine
7.1 h
Daylight
11.0 h

November

Driest
47°34°
Rain
9 days
Sunshine
5.8 h
Daylight
9.7 h
Snow
2 days

December

39°27°
Rain
10 days
Sunshine
4.1 h
Daylight
9.1 h
Snow
3 days

Looking for warmer alternatives? Browse warm places by month, or compare Ann Arbor's coolest part of the year: January, February, December.

Where Ann Arbor sits among other climates

  • 29% of the year's precipitation falls in its wettest three months - more evenly spread than all but 9% of the 3496 cities we track.
  • Ann Arbor averages 50°F (10°C) across the year - cooler than all but 11% of the 3496 cities we track.

These comparisons use the same ten-year window for every city in the dataset.

Questions about Ann Arbor's seasonal changes

How warm is Ann Arbor on average?
50°F (10°C) across all twelve months - about 58°F (15°C) by day and 42°F (6°C) after dark.
What should I pack for Ann Arbor?
It depends on the month: July runs to 82°F (28°C) while January holds at 32°F (0°C). The full month-by-month breakdown is in the packing notes above.
How much sun does Ann Arbor get?
8.2 hours a day averaged over the year, peaking in July at 12.2 hours.
How cold does Ann Arbor get in winter?
January nights average 19°F (-7°C). Frost and occasional ice are part of the season.
How humid does Ann Arbor get?
Relative humidity averages 71% across the year, which reads as fairly humid. The most comfortable stretch falls in the drier half of the year.
How many rainy days does Ann Arbor get in a year?
About 130 days bring measurable precipitation, totalling 36.7 inches (932 mm). That works out at roughly 7.2 mm on an average wet day.