Weather in Ann Arbor, Michigan
Roses open along the stoops. Day 58 of spring. Read this microseason across nine climate regions →
- TodayMay 16Light Drizzle35%81°52°
- SundayMay 17Overcast16%86°62°
- MondayMay 18Overcast31%83°63°
- TuesdayMay 19Showers77%82°66°
- WednesdayMay 20Light Drizzle71%67°46°
- ThursdayMay 21Overcast—58°42°
- FridayMay 22Light Drizzle15%65°43°
- PM 2.5
- 6.2 μg/m³
- PM 10
- 7.5 μg/m³
- NO₂
- 2.5 μg/m³
- Ozone
- 120.0 μg/m³
- UV Index
- 0.5 Low
Flowers blooming in late autumn, a sure sign of a bad winter coming.
- Moonrise
- 9:33 AM
- Moonset
- 12:02 AM
- In sign
- ♉︎ Taurus
Roses open along the stoops
Ann Arbor at a glance
- Today vs. normal: 9°F above the seasonal normal for this latitude
- Last frost: April 30 (climatological average for this latitude)
- Microseason: 28 of 72, May 16–20
- Planting window: Direct sow okra, melons, and southern peas. Thin carrot rows.
Right now in the garden
Cool-season window is open
As of May 16, the cool-season window is open or about to open. Direct-sow peas, lettuce, spinach, radishes, and brassicas now. Hold off on warm-season crops until 1–2 weeks after the last spring frost (around May).
Planting calendar
| Month | Plant | Harvest |
|---|---|---|
| January | — | — |
| February | — | — |
| March | — | — |
| April | — | — |
| May | lettuce, peas, spinach, radishes | lettuce, peas, radishes |
| June | lettuce, peas, spinach, radishes, tomatoes, peppers, beans, squash | lettuce, peas, radishes |
| July | tomatoes, peppers, beans, squash | tomatoes, beans, summer squash |
| August | tomatoes, peppers, beans, squash, fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| September | fall brassicas, garlic (overwinter), carrots | tomatoes, beans, summer squash |
| October | — | winter squash, tomatoes (last) |
| November | — | — |
| December | — | — |
A year in weather
July stands as Ann Arbor's warmest month with average temperatures around 72°F, while January marks the coldest period at roughly 24°F. The wettest conditions occur in June with 4.3 inches of rainfall, compared to February's drier 2.4 inches.
| Month | Mean temp | Precip | Rainy days |
|---|---|---|---|
| January | 24° | 2.8″ | 8 |
| February | 26° | 2.4″ | 6 |
| March | 35° | 2.8″ | 6 |
| April | 46° | 3.3″ | 7 |
| May | 58° | 3.8″ | 8 |
| June | 68° | 4.3″ | 7 |
| July | 72° | 3.9″ | 7 |
| August | 70° | 3.3″ | 6 |
| September | 62° | 3.0″ | 6 |
| October | 51° | 2.9″ | 7 |
| November | 39° | 2.7″ | 7 |
| December | 29° | 2.6″ | 7 |
Regional context
Ann Arbor falls within the warm-summer humid continental climate classification, sharing temperature patterns, seasonal rhythms, and growing conditions with other cities in this regional climate zone.
Similar climates: Detroit, MI, Grand Rapids, MI, Lansing, MI, Flint, MI, Kalamazoo, MI.
Naturalist notes
Late May brings the emergence of wild columbine blooms throughout local woodlands, their distinctive spurred flowers appearing as soil temperatures stabilize after the final frost.
American robins begin their second nesting cycle in early June, with pairs selecting fresh sites in maples and oaks as daylight stretches past 15 hours.
Frequently asked
- When does it freeze in Ann Arbor?
- Spring's final frost in Ann Arbor generally occurs around mid-May, while the first autumn frost typically arrives in mid-October.
- What is the rainy season in Ann Arbor?
- June records the highest monthly rainfall at approximately 4.3 inches, contributing to the city's annual total of roughly 38 inches.
- What is the warmest month in Ann Arbor?
- July typically delivers the year's warmest temperatures, averaging around 72°F.
- What is the coldest month in Ann Arbor?
- January brings the coldest conditions, with average temperatures near 24°F.
- When can I start a vegetable garden in Ann Arbor?
- Cool-season vegetables like peas and lettuce can be planted around the last spring frost in mid-May, while warm-season crops such as tomatoes and peppers should wait an additional 1–2 weeks.
- How many rainy days does Ann Arbor get?
- Ann Arbor experiences precipitation on approximately 82 days each year.
- What hardiness zone is Ann Arbor?
- Ann Arbor's USDA hardiness zone reflects its average minimum winter temperatures; the USDA's online tool can provide the current zone designation using the city's ZIP code.
Climate
Ann Arbor, Michigan experiences a warm-summer humid continental climate. Winter temperatures in January typically hover around 24°F, while July brings average highs of 72°F, creating a 48°F seasonal temperature range.
Throughout the year, the city receives approximately 38 inches of precipitation distributed across roughly 82 rainy days.
Local weather patterns respond to Ann Arbor's latitude at 42.3°N, the influence of nearby large water bodies, and regional elevation changes. These factors determine growing seasons, frost timing, and daily weather variations.