Frost Dates for Port Huron, MI
In Port Huron, MI, the average last spring frost is around Apr 19 and the average first fall frost around Nov 3, for a growing season of about 196 days. For frost-tender plants, wait until May 4, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Port Huron, MI weather station, 1 mile away, elevation 590 ft. Frost can come earlier in low spots and valleys and later near cities and large lakes.
Frost probability by date
Chance of a 32°F frost after the spring date, or before the fall date.
| Chance | Last spring frost | First fall frost |
|---|---|---|
| 10% | May 4 | Oct 20 |
| 20% | Apr 29 | Oct 25 |
| 30% | Apr 25 | Oct 30 |
| 40% | Apr 21 | Nov 1 |
| 50% | Apr 19 | Nov 3 |
| 60% | Apr 17 | Nov 5 |
| 70% | Apr 14 | Nov 8 |
| 80% | Apr 10 | Nov 11 |
| 90% | Apr 7 | Nov 16 |
Light frost vs. hard freeze
Average (50%) dates for each temperature. Tender plants are damaged at 36°F; most hardy crops survive until 28°F.
| Temperature | Last in spring | First in fall |
|---|---|---|
| Light frost (36°F) | May 1 | Oct 22 |
| Frost / freeze (32°F) | Apr 19 | Nov 3 |
| Hard freeze (28°F) | Apr 7 | Nov 12 |
Planting calendar for Port Huron
Transplant Apr 26 – May 10
Transplant May 3 – May 17
Transplant May 3 – May 17
Transplant Apr 26 – May 10
Sow or transplant Apr 26 – May 10
Sow or transplant Apr 26 – May 10
Sow or transplant May 3 – May 17
Sow or transplant Mar 22 – Apr 5
Fall sowing Sep 8 – Oct 6
Fall sowing Sep 8 – Sep 29
Fall sowing Aug 25 – Sep 8
Sow or transplant Mar 22 – Apr 5
Fall sowing Aug 25 – Sep 22
Transplant Apr 5 – Apr 19
Fall sowing Aug 11 – Aug 25
Transplant Mar 29 – Apr 12
Fall sowing Aug 11 – Aug 25
Fall sowing Aug 11 – Aug 25
Fall sowing Sep 22 – Oct 13
Fall sowing Aug 25 – Sep 8
Plant Mar 22 – Apr 5
Based on the average last frost (Apr 19) and first frost (Nov 3). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.