Last Frost Date Ann Arbor: Frost Dates, Late Frost Risk & Growing Season
When is the last spring frost and the first autumn frost in Ann Arbor? Frost dates from 30 years of data, the risk of late frost, frost-free days and planting dates.
The frost season in Ann Arbor
- Last frost (average): April 19
- In 1 year out of 10 it still freezes on May 8.
- First frost: November 1
- Frost-free season: 187 days
- Frost after 15 May: in 0 % of years
Frost days per month in Ann Arbor
- January: 27.1 · -7 °C
- February: 24.4 · -6 °C
- March: 20.2 · -2 °C
- April: 5.7 · 4 °C
- May: 0.2 · 10 °C
- June: 0 · 16 °C
- July: 0 · 18 °C
- August: 0 · 17 °C
- September: 0 · 13 °C
- October: 1 · 7 °C
- November: 13.4 · 1 °C
- December: 24.1 · -4 °C
- Matched to the average lows of a weather station 30 km away – accurate to about ±1–2 weeks.
- Daily minimum temperatures 2 m above ground over 30 years (1991–2020), NASA POWER; station data: Deutscher Wetterdienst (CC BY 4.0). Ground frost can form while the air at 2 m is still +2 to +3 °C.