Frost dates for 54311Green Bay, WI
The average last spring frost in Green Bay is May 7 and the average first fall frost is October 9, giving a typical growing season of about 154 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 7
- Average first fall frost
- Oct 9
- Growing season
- 154 days
Safer after May 22 (1-in-10 risk)
Possible by Sep 23 (1-in-10 risk)
Last frost typically in 193 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | May 4 · May 19 · May 31 | Sep 15 · Sep 28 · Oct 12 | 132 days | 100% |
| Frost / freeze (32°F) | Apr 24 · May 7 · May 22 | Sep 23 · Oct 9 · Oct 25 | 154 days | 100% |
| Hard freeze (28°F) | Apr 10 · Apr 27 · May 12 | Oct 5 · Oct 25 · Nov 7 | 180 days | 100% |
Planting calendar for Green Bay
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Apr 6 – Jun 12 |
| Tomatoes | Transplant outdoors | May 23 – Jun 19 |
| Peppers | Start seeds indoors | Apr 6 – May 7 |
| Peppers | Transplant outdoors | Jun 6 – Jul 7 |
| Eggplant | Start seeds indoors | Apr 23 – May 22 |
| Eggplant | Transplant outdoors | Jun 6 – Jul 7 |
| Cucumbers | Sow outdoors | Jun 6 – Jun 29 |
| Summer squash | Sow outdoors | May 23 – Jul 7 |
| Winter squash & pumpkins | Sow outdoors | Jun 6 – Jul 7 |
| Snap beans | Sow outdoors | May 23 – Jul 22 |
| Sweet corn | Sow outdoors | May 23 – Jun 19 |
| Watermelon & cantaloupe | Sow outdoors | Jun 6 – Jul 7 |
| Okra | Sow outdoors | May 30 – Jun 22 |
| Peas | Sow outdoors (spring) | Apr 6 – May 22 |
| Potatoes | Plant outdoors (spring) | Apr 6 – Jun 6 |
| Onions | Start seeds indoors (spring) | Feb 23 – Mar 22 |
| Onions | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (spring) | Mar 19 – Apr 22 |
| Broccoli | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (fall) | Jun 9 – Jun 19 |
| Broccoli | Transplant outdoors (fall) | Jul 9 – Jul 20 |
| Cabbage | Start seeds indoors (spring) | Mar 9 – Apr 6 |
| Cabbage | Transplant outdoors (spring) | Apr 6 – May 7 |
| Cabbage | Start seeds indoors (fall) | May 30 – Jun 29 |
| Cabbage | Transplant outdoors (fall) | Jun 29 – Jul 30 |
| Leaf lettuce | Sow outdoors (spring) | Apr 6 – Jun 22 |
| Leaf lettuce | Sow outdoors (fall) | Jun 29 – Aug 15 |
| Spinach | Sow outdoors (spring) | Mar 30 – May 13 |
| Spinach | Sow outdoors (fall) | Jul 16 – Aug 20 |
| Radishes | Sow outdoors (spring) | Apr 6 – May 27 |
| Radishes | Sow outdoors (fall) | Jun 29 – Aug 30 |
| Kale | Sow outdoors (spring) | Apr 23 – May 13 |
| Kale | Sow outdoors (fall) | Jun 22 – Jul 30 |
| Carrots | Sow outdoors (spring) | May 7 – Jun 22 |
| Carrots | Sow outdoors (fall) | May 30 – Jul 15 |
| Garlic | Plant outdoors (fall) | Sep 29 – Oct 30 |
Where these dates come from
ZIP code 54311 is matched to the NOAA station Green Bay Botanical, WI, 14.4 km away, at 694 ft elevation (67 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Green Bay Botanical, WI (used) | 694 ft | May 7 | Oct 9 |
| Green Bay, WI | 682 ft | Apr 30 | Oct 9 |
| Green Bay Wfo, WI | 682 ft | May 1 | Oct 11 |
| Denmark Wwtp, WI | 811 ft | May 6 | Oct 12 |
Frost dates near Green Bay
- Green Bay, WI 54302 · last Apr 30, first Oct 9
- New Franken, WI 54229 · last May 7, first Oct 9
- De Pere, WI 54115 · last Apr 30, first Oct 9
- Denmark, WI 54208 · last May 6, first Oct 12
- Luxemburg, WI 54217 · last May 1, first Oct 18
- Suamico, WI 54173 · last May 7, first Oct 9
- Oneida, WI 54155 · last May 1, first Oct 11
- Greenleaf, WI 54126 · last May 6, first Oct 6
Frequently asked questions
- When is the last frost in Green Bay, WI?
- For ZIP code 54311, the average last spring frost (32°F) is May 7, based on NOAA 1991-2020 climate normals for the Green Bay Botanical, WI weather station. There is a 1-in-10 chance of a frost after May 22.
- When is the first frost in Green Bay, WI?
- The average first fall frost (32°F) is October 9. There is a 1-in-10 chance of frost by September 23, so tender plants are at risk from that point on.
- How long is the growing season in 54311?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 154 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.