Port Huron, MI frost dates
Last spring frostApr 19median date
First fall frostNov 3median date
Growing season198 daysfrost-free
Hardiness zone6bZone 6b
How Port Huron compares
- In 8 years out of 10, the last spring frost in Port Huron falls between April 7 and May 4, a 27-day window. The first fall frost falls between October 20 and November 16.
- The median last frost is 16 days earlier than the Michigan median of May 5.
- Its 198-day growing season is among the longest of the 878 Michigan places with a regular frost season.
- The last frost is typical for zone 6b, where the median is Apr 22.
- The weather station records an average of 122 nights a year at or below 32°F.
- Compared with Clinton Township, MI, 59 km away, the last frost here is 11 days earlier than there and the growing season is 21 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 7 |
| 50% (median) | April 19 |
| 10% (safe for tender plants) | May 4 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 20 |
| 50% (median) | November 3 |
| 90% (late) | November 16 |
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 Port Huron, MI
Port Huron, MI frost dates — last frost Apr 19, first frost Nov 3, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Jan 25 to Feb 8Transplant outside: Mar 22 to Apr 5
Start indoors: Feb 8 to Feb 22Transplant outside: May 3 to May 17
Start indoors: Feb 8 to Feb 22Transplant outside: May 3 to May 17
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 26 to May 10
Start indoors: Feb 22 to Mar 8Transplant outside: Mar 29 to Apr 12Sow outdoors: Mar 22 to Apr 26Plant for fall: Sep 8 to Oct 6
Start indoors: Feb 22 to Mar 8Transplant outside: Mar 22 to Apr 5Sow outdoors: Mar 22 to Apr 5Plant for fall: Aug 25 to Sep 15
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 5 to Apr 19Plant for fall: Jul 28 to Aug 18
Start indoors: Feb 22 to Mar 8Transplant outside: Mar 29 to Apr 12Plant for fall: Jul 28 to Aug 18
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 5 to Apr 19Plant for fall: Jul 28 to Aug 18
Start indoors: Mar 8 to Mar 22Transplant outside: May 10 to May 24Sow outdoors: May 10 to May 24
Start indoors: Mar 8 to Mar 22Transplant outside: Apr 26 to May 10
Sow outdoors: Mar 8 to Mar 29Plant for fall: Aug 11 to Sep 1
Sow outdoors: Mar 8 to Mar 29Plant for fall: Sep 8 to Sep 29
Sow outdoors: Mar 15 to Apr 26Plant for fall: Sep 22 to Oct 13
Start indoors: Mar 22 to Mar 29Transplant outside: May 3 to May 10Sow outdoors: Apr 26 to May 10Plant for fall: Aug 18 to Sep 1
Start indoors: Mar 22 to Mar 29Sow outdoors: Apr 26 to May 10Plant for fall: Aug 25 to Sep 8
Start indoors: Mar 22 to Mar 29Sow outdoors: Apr 26 to May 10
Start indoors: Mar 22 to Mar 29Transplant outside: May 3 to May 17
Sow outdoors: Mar 29 to Apr 26Plant for fall: Aug 11 to Aug 25
Sow outdoors: Mar 29 to Apr 26Plant for fall: Aug 25 to Sep 8
Sow outdoors: Mar 29 to Apr 19
Sow outdoors: Apr 5 to May 3Plant for fall: Aug 25 to Sep 8
Sow outdoors: Apr 5 to Apr 26Plant for fall: Sep 8 to Sep 29
Sow outdoors: Apr 26 to May 17Plant for fall: Aug 18 to Sep 1
Sow outdoors: Apr 26 to May 10
Transplant outside: May 3 to May 24
Plant for fall: Oct 20 to Nov 24
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Port Huron, MI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 25 – Feb 8 | Mar 22 – Apr 5 | — | — |
| Peppers | Feb 8 – Feb 22 | May 3 – May 17 | — | — |
| Eggplant | Feb 8 – Feb 22 | May 3 – May 17 | — | — |
| Tomatoes | Feb 22 – Mar 8 | Apr 26 – May 10 | — | — |
| Lettuce | Feb 22 – Mar 8 | Mar 29 – Apr 12 | Mar 22 – Apr 26 | Sep 8 – Oct 6 |
| Kale | Feb 22 – Mar 8 | Mar 22 – Apr 5 | Mar 22 – Apr 5 | Aug 25 – Sep 15 |
| Broccoli | Feb 22 – Mar 8 | Apr 5 – Apr 19 | — | Jul 28 – Aug 18 |
| Cabbage | Feb 22 – Mar 8 | Mar 29 – Apr 12 | — | Jul 28 – Aug 18 |
| Cauliflower | Feb 22 – Mar 8 | Apr 5 – Apr 19 | — | Jul 28 – Aug 18 |
| Okra | Mar 8 – Mar 22 | May 10 – May 24 | May 10 – May 24 | — |
| Basil | Mar 8 – Mar 22 | Apr 26 – May 10 | — | — |
| Peas | — | — | Mar 8 – Mar 29 | Aug 11 – Sep 1 |
| Spinach | — | — | Mar 8 – Mar 29 | Sep 8 – Sep 29 |
| Radishes | — | — | Mar 15 – Apr 26 | Sep 22 – Oct 13 |
| Cucumbers | Mar 22 – Mar 29 | May 3 – May 10 | Apr 26 – May 10 | Aug 18 – Sep 1 |
| Zucchini & Summer Squash | Mar 22 – Mar 29 | — | Apr 26 – May 10 | Aug 25 – Sep 8 |
| Winter Squash & Pumpkins | Mar 22 – Mar 29 | — | Apr 26 – May 10 | — |
| Melons & Watermelon | Mar 22 – Mar 29 | May 3 – May 17 | — | — |
| Carrots | — | — | Mar 29 – Apr 26 | Aug 11 – Aug 25 |
| Beets | — | — | Mar 29 – Apr 26 | Aug 25 – Sep 8 |
| Potatoes | — | — | Mar 29 – Apr 19 | — |
| Swiss Chard | — | — | Apr 5 – May 3 | Aug 25 – Sep 8 |
| Cilantro | — | — | Apr 5 – Apr 26 | Sep 8 – Sep 29 |
| Green Beans | — | — | Apr 26 – May 17 | Aug 18 – Sep 1 |
| Sweet Corn | — | — | Apr 26 – May 10 | — |
| Sweet Potatoes | — | May 3 – May 24 | — | — |
| Garlic | — | — | — | Oct 20 – Nov 24 |
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 Port Huron, MI weather station, 2 km away (elevation 591 ft (180 m)).
ZIP codes in Port Huron: 48060 48061
Frost dates near Port Huron
- Marysville Apr 19 · Nov 3
- North Street Apr 19 · Nov 3
- Fort Gratiot Apr 19 · Nov 3
- Smiths Creek Apr 19 · Nov 3
- Saint Clair Apr 19 · Nov 3
- Jeddo May 12 · Oct 5
- Goodells May 1 · Oct 20
- Columbus May 1 · Oct 20
- Avoca May 12 · Oct 5
- East China May 3 · Oct 18
Frequently asked questions
When is the last frost in Port Huron, MI?
The median last spring frost in Port Huron, MI is April 19. There is still about a 10% chance of frost after May 4, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Port Huron, MI?
The median first fall frost is November 3, with about a 10% chance of frost before October 20.
How long is the growing season in Port Huron, MI?
About 198 days between the median last spring frost and first fall frost.
What planting zone is Port Huron, MI?
Port Huron, MI is in USDA hardiness zone 6b.