Williamston, MI frost dates
Last spring frostApr 28median date
First fall frostOct 17median date
Growing season172 daysfrost-free
Hardiness zone6aZone 6a
How Williamston compares
- In 8 years out of 10, the last spring frost in Williamston falls between April 13 and May 16, a 33-day window. The first fall frost falls between October 1 and November 1.
- The median last frost is 7 days earlier than the Michigan median of May 5.
- Its 172-day growing season is longer than 75% of the 878 Michigan places with a regular frost season (state median 162 days).
- The last frost is typical for zone 6a, where the median is Apr 29.
- The weather station records an average of 145 nights a year at or below 32°F.
- Compared with Lansing, MI, 23 km away, the last frost here is 3 days earlier than there and the growing season is 7 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 13 |
| 50% (median) | April 28 |
| 10% (safe for tender plants) | May 16 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 1 |
| 50% (median) | October 17 |
| 90% (late) | November 1 |
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 Williamston, MI
Williamston, MI frost dates — last frost Apr 28, first frost Oct 17, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Feb 3 to Feb 17Transplant outside: Mar 31 to Apr 14
Start indoors: Feb 17 to Mar 3Transplant outside: May 12 to May 26
Start indoors: Feb 17 to Mar 3Transplant outside: May 12 to May 26
Start indoors: Mar 3 to Mar 17Transplant outside: May 5 to May 19
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 7 to Apr 21Sow outdoors: Mar 31 to May 5Plant for fall: Aug 22 to Sep 19
Start indoors: Mar 3 to Mar 17Transplant outside: Mar 31 to Apr 14Sow outdoors: Mar 31 to Apr 14Plant for fall: Aug 8 to Aug 29
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 14 to Apr 28Plant for fall: Jul 11 to Aug 1
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 7 to Apr 21Plant for fall: Jul 11 to Aug 1
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 14 to Apr 28Plant for fall: Jul 11 to Aug 1
Start indoors: Mar 17 to Mar 31Transplant outside: May 19 to Jun 2Sow outdoors: May 19 to Jun 2
Start indoors: Mar 17 to Mar 31Transplant outside: May 5 to May 19
Sow outdoors: Mar 17 to Apr 7Plant for fall: Jul 25 to Aug 15
Sow outdoors: Mar 17 to Apr 7Plant for fall: Aug 22 to Sep 12
Sow outdoors: Mar 24 to May 5Plant for fall: Sep 5 to Sep 26
Start indoors: Mar 31 to Apr 7Transplant outside: May 12 to May 19Sow outdoors: May 5 to May 19Plant for fall: Aug 1 to Aug 15
Start indoors: Mar 31 to Apr 7Sow outdoors: May 5 to May 19Plant for fall: Aug 8 to Aug 22
Start indoors: Mar 31 to Apr 7Sow outdoors: May 5 to May 19
Start indoors: Mar 31 to Apr 7Transplant outside: May 12 to May 26
Sow outdoors: Apr 7 to May 5Plant for fall: Jul 25 to Aug 8
Sow outdoors: Apr 7 to May 5Plant for fall: Aug 8 to Aug 22
Sow outdoors: Apr 7 to Apr 28
Sow outdoors: Apr 14 to May 12Plant for fall: Aug 8 to Aug 22
Sow outdoors: Apr 14 to May 5Plant for fall: Aug 22 to Sep 12
Sow outdoors: May 5 to May 26Plant for fall: Aug 1 to Aug 15
Sow outdoors: May 5 to May 19
Transplant outside: May 12 to Jun 2
Plant for fall: Oct 3 to Nov 7
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Williamston, MI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 3 – Feb 17 | Mar 31 – Apr 14 | — | — |
| Peppers | Feb 17 – Mar 3 | May 12 – May 26 | — | — |
| Eggplant | Feb 17 – Mar 3 | May 12 – May 26 | — | — |
| Tomatoes | Mar 3 – Mar 17 | May 5 – May 19 | — | — |
| Lettuce | Mar 3 – Mar 17 | Apr 7 – Apr 21 | Mar 31 – May 5 | Aug 22 – Sep 19 |
| Kale | Mar 3 – Mar 17 | Mar 31 – Apr 14 | Mar 31 – Apr 14 | Aug 8 – Aug 29 |
| Broccoli | Mar 3 – Mar 17 | Apr 14 – Apr 28 | — | Jul 11 – Aug 1 |
| Cabbage | Mar 3 – Mar 17 | Apr 7 – Apr 21 | — | Jul 11 – Aug 1 |
| Cauliflower | Mar 3 – Mar 17 | Apr 14 – Apr 28 | — | Jul 11 – Aug 1 |
| Okra | Mar 17 – Mar 31 | May 19 – Jun 2 | May 19 – Jun 2 | — |
| Basil | Mar 17 – Mar 31 | May 5 – May 19 | — | — |
| Peas | — | — | Mar 17 – Apr 7 | Jul 25 – Aug 15 |
| Spinach | — | — | Mar 17 – Apr 7 | Aug 22 – Sep 12 |
| Radishes | — | — | Mar 24 – May 5 | Sep 5 – Sep 26 |
| Cucumbers | Mar 31 – Apr 7 | May 12 – May 19 | May 5 – May 19 | Aug 1 – Aug 15 |
| Zucchini & Summer Squash | Mar 31 – Apr 7 | — | May 5 – May 19 | Aug 8 – Aug 22 |
| Winter Squash & Pumpkins | Mar 31 – Apr 7 | — | May 5 – May 19 | — |
| Melons & Watermelon | Mar 31 – Apr 7 | May 12 – May 26 | — | — |
| Carrots | — | — | Apr 7 – May 5 | Jul 25 – Aug 8 |
| Beets | — | — | Apr 7 – May 5 | Aug 8 – Aug 22 |
| Potatoes | — | — | Apr 7 – Apr 28 | — |
| Swiss Chard | — | — | Apr 14 – May 12 | Aug 8 – Aug 22 |
| Cilantro | — | — | Apr 14 – May 5 | Aug 22 – Sep 12 |
| Green Beans | — | — | May 5 – May 26 | Aug 1 – Aug 15 |
| Sweet Corn | — | — | May 5 – May 19 | — |
| Sweet Potatoes | — | May 12 – Jun 2 | — | — |
| Garlic | — | — | — | Oct 3 – Nov 7 |
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 East Lansing 4 S, MI weather station, 16 km away (elevation 879 ft (268 m)).
Frost dates near Williamston
- Okemos Apr 28 · Oct 17
- Haslett Apr 28 · Oct 17
- Webberville May 4 · Oct 7
- Shaftsburg Apr 28 · Oct 17
- Perry May 1 · Oct 15
- East Lansing Apr 28 · Oct 17
- Dansville Apr 28 · Oct 17
- Morrice May 3 · Oct 11
- Fowlerville May 4 · Oct 7
- Mason Apr 28 · Oct 17
Frequently asked questions
When is the last frost in Williamston, MI?
The median last spring frost in Williamston, MI is April 28. There is still about a 10% chance of frost after May 16, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Williamston, MI?
The median first fall frost is October 17, with about a 10% chance of frost before October 1.
How long is the growing season in Williamston, MI?
About 172 days between the median last spring frost and first fall frost.
What planting zone is Williamston, MI?
Williamston, MI is in USDA hardiness zone 6a.