Frost dates for 54305Green Bay, WI
The average last spring frost in Green Bay is April 30 and the average first fall frost is October 9, giving a typical growing season of about 161 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 30
- Average first fall frost
- Oct 9
- Growing season
- 161 days
Safer after May 16 (1-in-10 risk)
Possible by Sep 24 (1-in-10 risk)
Last frost typically in 181 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) | Apr 29 · May 13 · May 27 | Sep 16 · Sep 29 · Oct 12 | 140 days | 100% |
| Frost / freeze (32°F) | Apr 16 · Apr 30 · May 16 | Sep 24 · Oct 9 · Oct 26 | 161 days | 100% |
| Hard freeze (28°F) | Apr 3 · Apr 17 · May 4 | Oct 6 · Oct 24 · Nov 9 | 187 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 | Mar 30 – Jun 5 |
| Tomatoes | Transplant outdoors | May 16 – Jun 19 |
| Peppers | Start seeds indoors | Mar 30 – Apr 30 |
| Peppers | Transplant outdoors | May 30 – Jun 30 |
| Eggplant | Start seeds indoors | Apr 16 – May 15 |
| Eggplant | Transplant outdoors | May 30 – Jun 30 |
| Cucumbers | Sow outdoors | May 30 – Jun 29 |
| Summer squash | Sow outdoors | May 16 – Jun 30 |
| Winter squash & pumpkins | Sow outdoors | May 30 – Jun 30 |
| Snap beans | Sow outdoors | May 16 – Jul 22 |
| Sweet corn | Sow outdoors | May 16 – Jun 19 |
| Watermelon & cantaloupe | Sow outdoors | May 30 – Jun 30 |
| Okra | Sow outdoors | May 23 – Jun 15 |
| Peas | Sow outdoors (spring) | Mar 30 – May 15 |
| Potatoes | Plant outdoors (spring) | Mar 30 – May 30 |
| Onions | Start seeds indoors (spring) | Feb 16 – Mar 15 |
| Onions | Transplant outdoors (spring) | Apr 16 – May 15 |
| Broccoli | Start seeds indoors (spring) | Mar 12 – Apr 15 |
| Broccoli | Transplant outdoors (spring) | Apr 16 – May 15 |
| Broccoli | Start seeds indoors (fall) | Jun 9 – Jun 19 |
| Broccoli | Transplant outdoors (fall) | Jul 9 – Jul 20 |
| Cabbage | Start seeds indoors (spring) | Mar 2 – Mar 30 |
| Cabbage | Transplant outdoors (spring) | Mar 30 – Apr 30 |
| Cabbage | Start seeds indoors (fall) | May 30 – Jun 29 |
| Cabbage | Transplant outdoors (fall) | Jun 29 – Jul 30 |
| Leaf lettuce | Sow outdoors (spring) | Mar 30 – Jun 15 |
| Leaf lettuce | Sow outdoors (fall) | Jun 29 – Aug 15 |
| Spinach | Sow outdoors (spring) | Mar 23 – May 6 |
| Spinach | Sow outdoors (fall) | Jul 16 – Aug 20 |
| Radishes | Sow outdoors (spring) | Mar 30 – May 20 |
| Radishes | Sow outdoors (fall) | Jun 29 – Aug 30 |
| Kale | Sow outdoors (spring) | Apr 16 – May 6 |
| Kale | Sow outdoors (fall) | Jun 22 – Jul 30 |
| Carrots | Sow outdoors (spring) | Apr 30 – Jun 15 |
| Carrots | Sow outdoors (fall) | May 30 – Jul 15 |
| Garlic | Plant outdoors (fall) | Sep 29 – Oct 30 |
Where these dates come from
ZIP code 54305 is matched to the NOAA station Green Bay, WI, 9.3 km away, at 682 ft elevation (98 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Green Bay, WI (used) | 682 ft | Apr 30 | Oct 9 |
| Green Bay Wfo, WI | 682 ft | May 1 | Oct 11 |
| Green Bay Botanical, WI | 694 ft | May 7 | Oct 9 |
| Denmark Wwtp, WI | 811 ft | May 6 | Oct 12 |
Frost dates near Green Bay
- Green Bay, WI 54307 · last Apr 30, first Oct 9
- De Pere, WI 54115 · last Apr 30, first Oct 9
- Oneida, WI 54155 · last May 1, first Oct 11
- Denmark, WI 54208 · last May 6, first Oct 12
- New Franken, WI 54229 · last May 7, first Oct 9
- Greenleaf, WI 54126 · last May 6, first Oct 6
- Wrightstown, WI 54180 · last May 1, first Oct 11
- Suamico, WI 54173 · last May 7, first Oct 9
Frequently asked questions
- When is the last frost in Green Bay, WI?
- For ZIP code 54305, the average last spring frost (32°F) is April 30, based on NOAA 1991-2020 climate normals for the Green Bay, WI weather station. There is a 1-in-10 chance of a frost after May 16.
- 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 24, so tender plants are at risk from that point on.
- How long is the growing season in 54305?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 161 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.