Roscommon, MI frost dates
How Roscommon compares
- In 8 years out of 10, the last spring frost in Roscommon falls between April 30 and June 3, a 34-day window. The first fall frost falls between September 6 and October 7.
- The median last frost is 14 days later than the Michigan median of May 5.
- Its 127-day growing season is longer than 7% of the 878 Michigan places with a regular frost season (state median 162 days).
- The last frost is 16 days later than the zone 5a median of May 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5a chart.
- The weather station records an average of 169 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 30 |
| 50% (median) | May 19 |
| 10% (safe for tender plants) | June 3 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 6 |
| 50% (median) | September 23 |
| 90% (late) | October 7 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Roscommon, MI
Roscommon, MI frost dates — last frost May 19, first frost Sep 23, zone 5a. whenisthelastfrost.com
When to plant vegetables in Roscommon, MI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 24 – Mar 10 | Apr 21 – May 5 | — | — |
| Peppers | Mar 10 – Mar 24 | Jun 2 – Jun 16 | — | — |
| Eggplant | Mar 10 – Mar 24 | Jun 2 – Jun 16 | — | — |
| Tomatoes | Mar 24 – Apr 7 | May 26 – Jun 9 | — | — |
| Lettuce | Mar 24 – Apr 7 | Apr 28 – May 12 | Apr 21 – May 26 | Jul 29 – Aug 26 |
| Kale | Mar 24 – Apr 7 | Apr 21 – May 5 | Apr 21 – May 5 | Jul 15 – Aug 5 |
| Broccoli | Mar 24 – Apr 7 | May 5 – May 19 | — | Jun 17 – Jul 8 |
| Cabbage | Mar 24 – Apr 7 | Apr 28 – May 12 | — | Jun 17 – Jul 8 |
| Cauliflower | Mar 24 – Apr 7 | May 5 – May 19 | — | Jun 17 – Jul 8 |
| Okra | Apr 7 – Apr 21 | Jun 9 – Jun 23 | Jun 9 – Jun 23 | — |
| Basil | Apr 7 – Apr 21 | May 26 – Jun 9 | — | — |
| Peas | — | — | Apr 7 – Apr 28 | Jul 1 – Jul 22 |
| Spinach | — | — | Apr 7 – Apr 28 | Jul 29 – Aug 19 |
| Radishes | — | — | Apr 14 – May 26 | Aug 12 – Sep 2 |
| Cucumbers | Apr 21 – Apr 28 | Jun 2 – Jun 9 | May 26 – Jun 9 | Jul 8 – Jul 22 |
| Zucchini & Summer Squash | Apr 21 – Apr 28 | — | May 26 – Jun 9 | Jul 15 – Jul 29 |
| Winter Squash & Pumpkins | Apr 21 – Apr 28 | — | May 26 – Jun 9 | — |
| Melons & Watermelon | Apr 21 – Apr 28 | Jun 2 – Jun 16 | — | — |
| Carrots | — | — | Apr 28 – May 26 | Jul 1 – Jul 15 |
| Beets | — | — | Apr 28 – May 26 | Jul 15 – Jul 29 |
| Potatoes | — | — | Apr 28 – May 19 | — |
| Swiss Chard | — | — | May 5 – Jun 2 | Jul 15 – Jul 29 |
| Cilantro | — | — | May 5 – May 26 | Jul 29 – Aug 19 |
| Green Beans | — | — | May 26 – Jun 16 | Jul 8 – Jul 22 |
| Sweet Corn | — | — | May 26 – Jun 9 | — |
| Sweet Potatoes | — | Jun 2 – Jun 23 | — | — |
| Garlic | — | — | — | Sep 9 – Oct 14 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Houghton Lk Roscommon Ap, MI weather station, 14 km away (elevation 1,152 ft (351 m)).
Frost dates near Roscommon
- Higgins Lake May 19 · Sep 23
- Houghton Lake Heights May 20 · Oct 1
- Houghton Lake May 20 · Oct 1
- Prudenville May 19 · Sep 23
- Grayling May 23 · Sep 27
- Saint Helen May 19 · Sep 23
- Merritt May 30 · Sep 15
- Luzerne May 19 · Oct 2
- Lake City May 22 · Sep 26
- Falmouth May 30 · Sep 15
Frequently asked questions
When is the last frost in Roscommon, MI?
The median last spring frost in Roscommon, MI is May 19. There is still about a 10% chance of frost after June 3, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Roscommon, MI?
The median first fall frost is September 23, with about a 10% chance of frost before September 6.
How long is the growing season in Roscommon, MI?
About 127 days between the median last spring frost and first fall frost.
What planting zone is Roscommon, MI?
Roscommon, MI is in USDA hardiness zone 5a.