When Is the Last Frost in Michigan?
The average last spring frost in Michigan falls between April 27 and May 23 for most ZIP codes, with a statewide median of May 3. At the average date a later frost is still a coin flip, so tender plants wait for the safer 90% date.
| City | Last frost | 90% safe after | First frost | Growing season |
|---|---|---|---|---|
| Detroit | Apr 27 | May 11 | Oct 25 | 181 days |
| Grand Rapids | May 6 | May 23 | Oct 10 | 157 days |
| Warren | Apr 21 | May 6 | Oct 31 | 190 days |
| Sterling Heights | Apr 30 | May 15 | Oct 24 | 174 days |
| Ann Arbor | May 5 | May 20 | Oct 10 | 157 days |
| Lansing | May 1 | May 18 | Oct 13 | 162 days |
| Dearborn | Apr 27 | May 11 | Oct 25 | 181 days |
| Livonia | May 1 | May 16 | Oct 17 | 165 days |
| Troy | Apr 26 | May 12 | Oct 22 | 177 days |
| Farmington Hills | May 1 | May 16 | Oct 17 | 165 days |
| Flint | May 3 | May 20 | Oct 13 | 162 days |
| Kalamazoo | Apr 28 | May 13 | Oct 18 | 172 days |
| Battle Creek | Apr 30 | May 17 | Oct 19 | 170 days |
| Saginaw | Apr 29 | May 13 | Oct 21 | 175 days |
| Midland | Apr 29 | May 16 | Oct 16 | 167 days |
| Muskegon | Apr 30 | May 18 | Oct 19 | 170 days |
| Holland | Apr 28 | May 16 | Oct 21 | 175 days |
| Jackson | May 1 | May 18 | Oct 14 | 164 days |
| Marquette | May 8 | May 23 | Oct 21 | 164 days |
| Sault Ste. Marie | May 9 | May 27 | Oct 11 | 151 days |
| Escanaba | May 13 | May 31 | Oct 7 | 147 days |
Last and first frost: 50% (median) dates of the last spring and first fall 32 °F night. 90% safe after: only a 10% chance of a later spring frost. First frost dates in January fall in the following winter. Each city uses the NOAA station nearest the ZIP code closest to its center.
Across all 211 Michigan weather stations with frost records, median last frost dates run from April 17 at S Haven, MI to June 7 at Vanderbilt 11 ENE, MI. Elevation, valleys that collect cold air and distance from large water bodies explain most of the spread, so a garden a few miles from a listed city can differ by a week or more. The ZIP code lookup above uses the same NOAA data as the frost date calculator for every US ZIP code.
When Is the First Frost in Michigan?
The average first fall frost in Michigan arrives between September 28 and October 24 for most ZIP codes, with a median of October 13. Tomatoes, peppers, basil and squash are damaged at 32 °F, so harvest or cover them before then.
Fall frost can come early: Detroit has a 10% chance of frost before October 10, Grand Rapids has a 10% chance of frost before September 29 and Warren has a 10% chance of frost before October 17. Hardy crops such as kale, spinach and cabbage tolerate light frosts and keep producing after the first frost date.
When to Plant Tomatoes in Michigan?
Transplant tomatoes in Michigan 1 to 2 weeks after the local average last frost, once nights stay above about 50 °F: May 4 – May 11 in Detroit, May 13 – May 20 in Grand Rapids and Apr 28 – May 5 in Warren. Start seeds indoors 6 to 8 weeks before the last frost.
| City | Start seeds indoors | Transplant outdoors | Lowest-risk transplant |
|---|---|---|---|
| Detroit | Mar 2 – Mar 16 | May 4 – May 11 | after May 11 |
| Grand Rapids | Mar 11 – Mar 25 | May 13 – May 20 | after May 23 |
| Warren | Feb 24 – Mar 10 | Apr 28 – May 5 | after May 6 |
| Sterling Heights | Mar 5 – Mar 19 | May 7 – May 14 | after May 15 |
| Ann Arbor | Mar 10 – Mar 24 | May 12 – May 19 | after May 20 |
| Lansing | Mar 6 – Mar 20 | May 8 – May 15 | after May 18 |
| Dearborn | Mar 2 – Mar 16 | May 4 – May 11 | after May 11 |
| Livonia | Mar 6 – Mar 20 | May 8 – May 15 | after May 16 |
| Troy | Mar 1 – Mar 15 | May 3 – May 10 | after May 12 |
| Farmington Hills | Mar 6 – Mar 20 | May 8 – May 15 | after May 16 |
| Flint | Mar 8 – Mar 22 | May 10 – May 17 | after May 20 |
| Kalamazoo | Mar 3 – Mar 17 | May 5 – May 12 | after May 13 |
| Battle Creek | Mar 5 – Mar 19 | May 7 – May 14 | after May 17 |
| Saginaw | Mar 4 – Mar 18 | May 6 – May 13 | after May 13 |
| Midland | Mar 4 – Mar 18 | May 6 – May 13 | after May 16 |
| Muskegon | Mar 5 – Mar 19 | May 7 – May 14 | after May 18 |
| Holland | Mar 3 – Mar 17 | May 5 – May 12 | after May 16 |
| Jackson | Mar 6 – Mar 20 | May 8 – May 15 | after May 18 |
| Marquette | Mar 13 – Mar 27 | May 15 – May 22 | after May 23 |
| Sault Ste. Marie | Mar 14 – Mar 28 | May 16 – May 23 | after May 27 |
| Escanaba | Mar 18 – Apr 1 | May 20 – May 27 | after May 31 |
Indoors: 6–8 weeks before the average last frost. Outdoors: 1–2 weeks after it. Lowest-risk: after the date with only a 10% chance of a later frost. Rules of thumb; check the 10-day forecast and wait for soil near 60 °F.
Tomatoes stall below about 50 °F at night and are killed by frost, so a week or two of waiting after the average date costs little. The tomato plant care guide covers light, watering and feeding once plants are in the ground.
What Can You Plant in Detroit and When?
Detroit's average last frost of April 27 anchors its spring planting calendar: peas and spinach go in from March 16, broccoli and lettuce transplants from March 30, and tomatoes, peppers and squash after May 4.
| Crop | Start seeds indoors | Plant outdoors | Frost tolerance |
|---|---|---|---|
| Peas | — | Mar 16 – Mar 30direct sow, 4–6 weeks before last frost | hardy |
| Spinach | — | Mar 16 – Apr 6direct sow, 3–6 weeks before last frost | hardy |
| Radishes | — | Mar 23 – Apr 6direct sow, 3–5 weeks before last frost | hardy |
| Onions (sets) | — | Mar 30 – Apr 13plant, 2–4 weeks before last frost | hardy |
| Potatoes | — | Mar 30 – Apr 13plant, 2–4 weeks before last frost | half-hardy |
| Broccoli & cabbage | Mar 2 – Mar 16 | Mar 30 – Apr 13transplant, 2–4 weeks before last frost | hardy |
| Lettuce | Mar 16 – Mar 30 | Mar 30 – Apr 13transplant, 2–4 weeks before last frost | hardy |
| Beets | — | Mar 30 – Apr 13direct sow, 2–4 weeks before last frost | half-hardy |
| Carrots | — | Apr 6 – Apr 13direct sow, 2–3 weeks before last frost | half-hardy |
| Tomatoes | Mar 2 – Mar 16 | May 4 – May 11transplant, 1–2 weeks after last frost | tender |
| Basil | Mar 2 – Mar 16 | May 4 – May 18transplant, 1–3 weeks after last frost | tender |
| Peppers | Feb 16 – Mar 2 | May 11 – May 18transplant, 2–3 weeks after last frost | tender |
| Eggplant | Feb 16 – Mar 2 | May 11 – May 18transplant, 2–3 weeks after last frost | tender |
| Green beans | — | May 4 – May 18direct sow, 1–3 weeks after last frost | tender |
| Sweet corn | — | May 4 – May 18direct sow, 1–3 weeks after last frost | tender |
| Cucumbers | Mar 30 – Apr 6 | May 4 – May 18transplant, 1–3 weeks after last frost | tender |
| Squash & zucchini | Mar 30 – Apr 6 | May 4 – May 18transplant, 1–3 weeks after last frost | tender |
| Watermelon | Mar 30 – Apr 6 | May 11 – May 18transplant, 2–3 weeks after last frost | tender |
Dates for Detroit (last frost Apr 27, NOAA station Dearborn #2, MI, 4 miles from ZIP 48206). General rules of thumb; wait for soil near 50 °F for most seeds and 60 °F for beans, corn and squash.
How Long Is the Growing Season in Michigan?
The frost-free growing season in Michigan lasts about 128 to 178 days for most ZIP codes, with a median of 161 days. Among the listed cities, Escanaba has the shortest season at 147 days and Warren the longest at 190.
Season length decides which varieties ripen: compare it with the “days to maturity” on seed packets, counted from transplanting for tomatoes and peppers. NOAA stations in Michigan range from 94 days at Amasa 1 W, MI to 201 days at S Haven, MI. Planning beds before the season starts helps in short seasons — a plant spacing calculator for vegetable beds shows how many transplants fit.
What Hardiness Zones Are in Michigan?
Michigan spans USDA hardiness zones 4a to 7a, with zone 6a the most common. Zones describe winter cold and decide which perennials survive, while frost dates set when to plant annual vegetables and flowers.
The Michigan planting zone map with the zone of each city shows how the zones are spread across the state and which plants are hardy in all of them.
Frequently Asked Questions
- When is the last frost in Michigan?
- The average last spring frost in Michigan falls between April 27 and May 23 for most ZIP codes, with a statewide median of May 3. Among major cities it ranges from April 21 in Warren to May 13 in Escanaba.
- When is the last frost in Detroit, Michigan?
- Detroit's average last spring frost is April 27, and by May 11 the chance of a later frost drops to 10%. Its first fall frost averages October 25, giving a 181-day growing season (NOAA station Dearborn #2, MI).
- When should you plant tomatoes in Michigan?
- Transplant tomatoes in Michigan 1 to 2 weeks after the local average last frost, once nights stay above about 50 °F: May 4 – May 11 in Detroit, May 13 – May 20 in Grand Rapids and Apr 28 – May 5 in Warren. Start seeds indoors 6 to 8 weeks before the last frost.
- When is the first frost in Michigan?
- The average first fall frost in Michigan arrives between September 28 and October 24 for most ZIP codes, with a median of October 13. Harvest tender crops such as tomatoes, peppers and basil before then or cover them on cold nights.
- How long is the growing season in Michigan?
- The frost-free growing season in Michigan lasts about 128 to 178 days for most ZIP codes, with a median of 161 days, from 147 days in Escanaba to 190 days in Warren.
Frost data: NOAA National Centers for Environmental Information, 1991–2020 U.S. Climate Normals (32 °F freeze dates by probability). ZIP code and city locations and populations: U.S. Census Bureau Gazetteer files and Vintage 2024 population estimates. Planting windows are general rules of thumb. PlantoScan is not affiliated with or endorsed by these agencies.