Frost Dates for Green Bay, WI
In Green Bay, WI, the average last spring frost is around May 7 and the average first fall frost around Oct 9, for a growing season of about 154 days. For frost-tender plants, wait until May 22, when the chance of frost drops to 10%.
Based on NOAA 1991–2020 records from the Green Bay Botanical, WI weather station, 6 miles away, elevation 694 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 22 | Sep 23 |
| 20% | May 16 | Sep 28 |
| 30% | May 13 | Oct 2 |
| 40% | May 10 | Oct 6 |
| 50% | May 7 | Oct 9 |
| 60% | May 4 | Oct 12 |
| 70% | May 2 | Oct 16 |
| 80% | Apr 29 | Oct 20 |
| 90% | Apr 24 | 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 19 | Sep 28 |
| Frost / freeze (32°F) | May 7 | Oct 9 |
| Hard freeze (28°F) | Apr 27 | Oct 25 |
Planting calendar for Green Bay
Transplant May 14 – May 28
Transplant May 21 – Jun 4
Transplant May 21 – Jun 4
Transplant May 14 – May 28
Sow or transplant May 14 – May 28
Sow or transplant May 14 – May 28
Sow or transplant May 21 – Jun 4
Sow or transplant Apr 9 – Apr 23
Fall sowing Aug 14 – Sep 11
Fall sowing Aug 14 – Sep 4
Fall sowing Jul 31 – Aug 14
Sow or transplant Apr 9 – Apr 23
Fall sowing Jul 31 – Aug 28
Transplant Apr 23 – May 7
Fall sowing Jul 17 – Jul 31
Transplant Apr 16 – Apr 30
Fall sowing Jul 17 – Jul 31
Fall sowing Jul 17 – Jul 31
Fall sowing Aug 28 – Sep 18
Fall sowing Jul 31 – Aug 14
Plant Apr 9 – Apr 23
Based on the average last frost (May 7) and first frost (Oct 9). The dashed lines mark those dates. Seed packets list days to maturity; adjust for your varieties.