Frost Dates for Plymouth, MN
In Plymouth, MN, the average last spring frost is around Apr 29 and the average first fall frost around Oct 12, for a growing season of about 163 days. For frost-tender plants, wait until May 12, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the New Hope, MN weather station, 4 miles away, elevation 910 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 12 | Sep 29 |
| 20% | May 7 | Oct 2 |
| 30% | May 4 | Oct 5 |
| 40% | May 1 | Oct 9 |
| 50% | Apr 29 | Oct 12 |
| 60% | Apr 26 | Oct 15 |
| 70% | Apr 23 | Oct 18 |
| 80% | Apr 19 | Oct 21 |
| 90% | Apr 15 | Oct 25 |
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 8 | Oct 1 |
| Frost / freeze (32°F) | Apr 29 | Oct 12 |
| Hard freeze (28°F) | Apr 19 | Oct 22 |
Planting calendar for Plymouth
Transplant May 6 – May 20
Transplant May 13 – May 27
Transplant May 13 – May 27
Transplant May 6 – May 20
Sow or transplant May 6 – May 20
Sow or transplant May 6 – May 20
Sow or transplant May 13 – May 27
Sow or transplant Apr 1 – Apr 15
Fall sowing Aug 17 – Sep 14
Fall sowing Aug 17 – Sep 7
Fall sowing Aug 3 – Aug 17
Sow or transplant Apr 1 – Apr 15
Fall sowing Aug 3 – Aug 31
Transplant Apr 15 – Apr 29
Fall sowing Jul 20 – Aug 3
Transplant Apr 8 – Apr 22
Fall sowing Jul 20 – Aug 3
Fall sowing Jul 20 – Aug 3
Fall sowing Aug 31 – Sep 21
Fall sowing Aug 3 – Aug 17
Plant Apr 1 – Apr 15
Based on the average last frost (Apr 29) and first frost (Oct 12). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.