Frost dates in Detroit, Michigan
NOAA 1991–2020 normals for a 32 °F freeze. Low spots and the edge of town run colder than downtown.
Short answer
The average last spring frost in Detroit is April 21, and the average first fall frost is October 31, from NOAA's Detroit City Airport station, 5 miles from the middle of Detroit. 1 year in 10 the last frost comes after May 6, and the first one by October 17. That leaves about 193 frost-free days. Detroit is in USDA planting zone 6b.
Weather stations around Detroit
The first row is the date most people in Detroit go by. The others show how far the dates move across the area.
| Station | Last spring frost | First fall frost | Frost-free |
|---|---|---|---|
| Detroit City Airport 5 mi away, 626 ft | April 21 1 in 10 after May 6 | October 31 1 in 10 by October 17 | 193 days |
| Dearborn #2 4 mi away, 605 ft | April 27 1 in 10 after May 11 | October 25 1 in 10 by October 10 | 181 days |
| Dearborn 8 mi away, 605 ft | May 1 1 in 10 after May 18 | October 15 1 in 10 by October 1 | 167 days |
| Grosse Pointe Farms 11 mi away, 613 ft | April 29 1 in 10 after May 13 | October 22 1 in 10 by October 7 | 176 days |
| Farmington 14 mi away, 720 ft | May 1 1 in 10 after May 16 | October 17 1 in 10 by October 1 | 169 days |
Distances are from the middle of Detroit as the Census Bureau maps it. The average date is NOAA's 50% date: half of years have a later last frost, or an earlier first one. Plan by the 1-in-10 date if a freeze would cost you plants. The planting zone is the USDA 2023 zone for ZIP code 48206, at the middle of the city.
Your exact ZIP code
Detroit covers a lot of ground. For the station nearest your own street, and its planting zone, type your ZIP code.
How these dates work
Frost dates come from NOAA's 1991 to 2020 Climate Normals, which work out from each weather station's daily lows how likely the last spring freeze and the first fall freeze (32 °F) are by each date. We use the station nearest the middle of your ZIP code and show its height and distance, since a station on a hill or by a lake can differ from your yard.
The average date is the 50% date: half of years have a freeze after the spring date or before the fall one. The 1-in-10 dates are NOAA's 10% dates, the ones to plan by if a late freeze would cost you plants. Within one yard, cold air pools in low spots while walls and paving hold heat, so some corners freeze before others.
More frost dates
All of Michigan, station by station.
Other Michigan cities: Grand Rapids
Nearby: Toledo, OH · Cleveland, OH · Akron, OH
Where the numbers come from
- USDA Plant Hardiness Zone Map, 2023. Agricultural Research Service, U.S. Department of Agriculture
- PRISM Climate Group, Oregon State University (zone data)
- NOAA NCEI, U.S. Climate Normals 1991–2020, annual/seasonal
- NOAA, Normals calculation methodology (frost-freeze probability dates)
- US Census Bureau, 2025 ZCTA gazetteer (ZIP code centers)
- US Census Bureau, 2025 city population estimates and place gazetteer