Ann Arbor University of Michigan, Michigan climate: Climate normals at a NOAA weather station
Ann Arbor University of Michigan's normal year runs from 16°F January nights to 84°F July afternoons, with 38.3 inches of precipitation and 61 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 9.3°C, January lows of −9°C, July highs of 29°C, 972 mm of precipitation a year.
- NOAA stationAnn Arbor University of Michigan
- Station IDUSC00200230
- Location42.30°N 83.66°W
- Elevation813 ft (248 m)
On October 22, the normal high in Ann Arbor University of Michigan is 59°F and the normal low 39°F, and the chance of measurable rain or snow is 42%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Ann Arbor University of Michigan.
- Jan 32° 16°
- Feb 35° 18°
- Mar 46° 25°
- Apr 60° 36°
- May 71° 47°
- Jun 80° 56°
- Jul 84° 60°
- Aug 82° 59°
- Sep 75° 52°
- Oct 62° 41°
- Nov 48° 31°
- Dec 36° 22°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Ann Arbor University of Michigan each month?
July is the warmest month, with normal highs of 84°F; January the coldest, with normal lows of 16°F. The most precipitation falls in June (3.91 in), the least in February (2.51 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 32°F | 16°F | 24.0°F | 2.96 | 18.3 | 18 | <1 | 28 | 9 h 20 min |
| February | 35°F | 18°F | 26.5°F | 2.51 | 15.3 | 14 | <1 | 25 | 10 h 30 min |
| March | 46°F | 25°F | 35.7°F | 2.82 | 8.3 | 14 | <1 | 22 | 11 h 50 min |
| April | 60°F | 36°F | 47.6°F | 3.44 | 2.6 | 14 | <1 | 9 | 13 h 20 min |
| May | 71°F | 47°F | 59.0°F | 3.84 | 0.0 | 15 | <1 | 1 | 14 h 30 min |
| June | 80°F | 56°F | 68.0°F | 3.91 | 0.0 | 12 | 3 | <1 | 15 h 20 min |
| July | 84°F | 60°F | 71.9°F | 3.52 | 0.0 | 12 | 6 | <1 | 15 h |
| August | 82°F | 59°F | 70.3°F | 3.52 | 0.0 | 11 | 2 | <1 | 14 h |
| September | 75°F | 52°F | 63.3°F | 3.18 | 0.0 | 11 | 1 | <1 | 12 h 30 min |
| October | 62°F | 41°F | 51.4°F | 2.99 | 0.1 | 13 | <1 | 4 | 11 h 10 min |
| November | 48°F | 31°F | 39.2°F | 2.82 | 4.1 | 14 | <1 | 16 | 9 h 50 min |
| December | 36°F | 22°F | 29.2°F | 2.75 | 12.7 | 17 | <1 | 26 | 9 h 10 min |
| Year (annual) | 59°F | 38°F | 48.8°F | 38.26 | 61.4 | 166 | 12 | 130 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −9°C | −4.4°C | 75 mm | 46 cm |
| February | 2°C | −8°C | −3.1°C | 64 mm | 39 cm |
| March | 8°C | −4°C | 2.1°C | 72 mm | 21 cm |
| April | 15°C | 2°C | 8.7°C | 87 mm | 7 cm |
| May | 22°C | 8°C | 15.0°C | 98 mm | 0 cm |
| June | 27°C | 13°C | 20.0°C | 99 mm | 0 cm |
| July | 29°C | 16°C | 22.2°C | 89 mm | 0 cm |
| August | 28°C | 15°C | 21.3°C | 89 mm | 0 cm |
| September | 24°C | 11°C | 17.4°C | 81 mm | 0 cm |
| October | 17°C | 5°C | 10.8°C | 76 mm | 0 cm |
| November | 9°C | −1°C | 4.0°C | 72 mm | 10 cm |
| December | 2°C | −5°C | −1.6°C | 70 mm | 32 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00200230; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
Which months are mildest at Ann Arbor University of Michigan?
Normal highs sit between 65°F and 85°F in May, June, July, August and September. Of those, September has the fewest days with rain (11).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00200230.
When is the last frost at Ann Arbor University of Michigan?
In Ann Arbor University of Michigan, the last spring frost (32°F) comes after May 3 in half of years and after May 20 in one year in ten; the first autumn frost comes before October 13 in half of years and before September 29 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- May 31 year in 10 after May 20; 9 in 10 after April 20
- First autumn frost, half of years before
- October 131 year in 10 before September 29; 9 in 10 before October 27
NOAA puts the median frost-free season at 160 days, and the season without a hard freeze (28°F) at 183 days.
A hard freeze (28°F) comes after April 23 in half of springs and before October 26 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Ann Arbor University of Michigan in zone 6a in ZIP code 48105, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, the station is in zone 6a: the coldest night of a typical year reaches −6°F (30 complete years).
Frost dates for every NOAA station in Michigan · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00200230; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get at Ann Arbor University of Michigan?
In a normal year in Ann Arbor University of Michigan, 12 days a year reach 90°F, 130 nights fall to 32°F or colder and 166 days bring measurable precipitation.
- Days at 90°F or more
- 12a normal year
- Days at 100°F or more
- fewer than 1a normal year
- Nights at 32°F or colder
- 130a normal year
- Days that stay below freezing
- 45high of 32°F or less
- Days with 0.01 inch of precipitation
- 166a normal year
- Days with 1 inch of snow or more
- 19a normal year
The highest temperature in this station's record (since 1881) is 105°F, on July 24, 1934; the lowest is −23°F, on February 11, 1885.
The wettest calendar year on that record is 2011, with 51.03 in; the snowiest season is 1922–23, with 90.6 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00200230; records: ACIS (NOAA Regional Climate Centers), station USC00200230. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Ann Arbor University of Michigan?
Over a year 71% of the sunlight that would reach the ground under clear skies gets through the clouds at Ann Arbor University of Michigan, 3.8 kWh per square metre a day. July is the sunniest month (80%) and December the cloudiest (54%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 59% | 1.6 |
| February | 62% | 2.4 |
| March | 66% | 3.5 |
| April | 68% | 4.7 |
| May | 70% | 5.5 |
| June | 76% | 6.2 |
| July | 80% | 6.2 |
| August | 78% | 5.3 |
| September | 77% | 4.3 |
| October | 68% | 2.8 |
| November | 63% | 1.8 |
| December | 54% | 1.2 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How many heating and cooling degree days does Ann Arbor University of Michigan record?
A normal year at Ann Arbor University of Michigan brings 6,501 heating degree days, 21% more than the median U.S. place (5,373), and 653 cooling degree days, 28% fewer than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 2,801 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,269 | 0 |
| February | 1,077 | 0 |
| March | 909 | 1 |
| April | 526 | 4 |
| May | 226 | 40 |
| June | 44 | 134 |
| July | 8 | 222 |
| August | 15 | 178 |
| September | 118 | 69 |
| October | 427 | 7 |
| November | 773 | 0 |
| December | 1,110 | 0 |
| Year (annual) | 6,501 | 653 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00200230. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Have recent years at Ann Arbor University of Michigan been warmer than normal?
2025 averaged 49.2°F, 0.4°F above the 1991-2020 normal of 48.8°F. 5 of the 5 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 50.9°F | +2.1°F | 48.13 | 54.1 |
| 2022 | 49.1°F | +0.3°F | 32.87 | 54.3 |
| 2023 | 50.6°F | +1.8°F | 40.12 | 44.5 |
| 2024 | 52.2°F | +3.4°F | 42.17 | 44.3 |
| 2025 | 49.2°F | +0.4°F | 35.71 | 52.6 |
Over 113 complete years from 1890 to 2025, the station's annual mean temperature rose at a fitted 2.6°F per century (+0.15°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00200230; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Ann Arbor University of Michigan's climate compare?
Ann Arbor University of Michigan is warmer than 120 of the 140 places with their own NOAA record in Michigan, and wetter than 110. Across the 7,247 U.S. stations with normals, its annual mean of 48.8°F is warmer than 35%.
In the Köppen classification computed from these normals, Ann Arbor University of Michigan is Dfa: continental, no dry season, hot summer. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Which places near Ann Arbor University of Michigan share this climate record?
Barton Hills has no NOAA station with 1991-2020 normals of its own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Barton Hills, MI324 people · 5 mi W
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Ann Arbor University of Michigan's climate
What is the coldest month at Ann Arbor University of Michigan?
January, with a normal high of 32°F and a normal low of 16°F. The warmest is July (84°F by day, 60°F at night).
Does it snow at Ann Arbor University of Michigan?
Yes: 61 inches in a normal year, falling on 55 days with 0.1 inch or more, the most in January (18.3 inches).
What is the rainiest month at Ann Arbor University of Michigan?
June, with 3.91 in of precipitation in a normal year; the driest is February with 2.51 in.
What plant hardiness zone is Ann Arbor University of Michigan in?
The USDA's 2023 map puts Ann Arbor University of Michigan in zone 6a in ZIP code 48105, the nearest ZIP area. By the same method at the station, the coldest night of a typical year reaches −6°F (30 years, 1991-2020): zone 6a.
How late can frost come at Ann Arbor University of Michigan?
In half of years the last 32°F night comes after May 3; in one year in ten it comes after May 20. Waiting until May 20 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Michigan climateThe statewide normals and every place in the state
- Ann Arbor SE, MI4 miles from this station, 48.2°F a year
- Ann Arbor, MI7 miles from this station, 47.8°F a year
- Saline, MI11 miles from this station, 48.2°F a year
- Whitmore Lake, MI11 miles from this station, 47.1°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made