Frost dates for 53070Oostburg, WI
The average last spring frost in Oostburg is May 3 and the average first fall frost is October 16, giving a typical growing season of about 165 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 3
- Average first fall frost
- Oct 16
- Growing season
- 165 days
Safer after May 18 (1-in-10 risk)
Possible by Oct 2 (1-in-10 risk)
Last frost typically in 188 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 1 · May 15 · May 30 | Sep 24 · Oct 4 · Oct 17 | 143 days | 100% |
| Frost / freeze (32°F) | Apr 18 · May 3 · May 18 | Oct 2 · Oct 16 · Oct 29 | 165 days | 100% |
| Hard freeze (28°F) | Apr 5 · Apr 20 · May 5 | Oct 13 · Oct 28 · Nov 10 | 189 days | 100% |
Planting calendar for Oostburg
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 2 – Jun 8 |
| Tomatoes | Transplant outdoors | May 19 – Jun 26 |
| Peppers | Start seeds indoors | Apr 2 – May 3 |
| Peppers | Transplant outdoors | Jun 2 – Jul 3 |
| Eggplant | Start seeds indoors | Apr 19 – May 18 |
| Eggplant | Transplant outdoors | Jun 2 – Jul 3 |
| Cucumbers | Sow outdoors | Jun 2 – Jul 6 |
| Summer squash | Sow outdoors | May 19 – Jul 3 |
| Winter squash & pumpkins | Sow outdoors | Jun 2 – Jul 3 |
| Snap beans | Sow outdoors | May 19 – Jul 29 |
| Sweet corn | Sow outdoors | May 19 – Jun 26 |
| Watermelon & cantaloupe | Sow outdoors | Jun 2 – Jul 3 |
| Okra | Sow outdoors | May 26 – Jun 18 |
| Peas | Sow outdoors (spring) | Apr 2 – May 18 |
| Potatoes | Plant outdoors (spring) | Apr 2 – Jun 2 |
| Onions | Start seeds indoors (spring) | Feb 19 – Mar 18 |
| Onions | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (spring) | Mar 15 – Apr 18 |
| Broccoli | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (fall) | Jun 16 – Jun 26 |
| Broccoli | Transplant outdoors (fall) | Jul 16 – Jul 27 |
| Cabbage | Start seeds indoors (spring) | Mar 5 – Apr 2 |
| Cabbage | Transplant outdoors (spring) | Apr 2 – May 3 |
| Cabbage | Start seeds indoors (fall) | Jun 6 – Jul 6 |
| Cabbage | Transplant outdoors (fall) | Jul 6 – Aug 6 |
| Leaf lettuce | Sow outdoors (spring) | Apr 2 – Jun 18 |
| Leaf lettuce | Sow outdoors (fall) | Jul 6 – Aug 22 |
| Spinach | Sow outdoors (spring) | Mar 26 – May 9 |
| Spinach | Sow outdoors (fall) | Jul 23 – Aug 27 |
| Radishes | Sow outdoors (spring) | Apr 2 – May 23 |
| Radishes | Sow outdoors (fall) | Jul 6 – Sep 6 |
| Kale | Sow outdoors (spring) | Apr 19 – May 9 |
| Kale | Sow outdoors (fall) | Jun 29 – Aug 6 |
| Carrots | Sow outdoors (spring) | May 3 – Jun 18 |
| Carrots | Sow outdoors (fall) | Jun 6 – Jul 22 |
| Garlic | Plant outdoors (fall) | Oct 6 – Nov 6 |
Where these dates come from
ZIP code 53070 is matched to the NOAA station Hingham Wwtp, WI, 9.3 km away, at 763 ft elevation (64 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Hingham Wwtp, WI (used) | 763 ft | May 3 | Oct 16 |
| Sheboygan Wwtp, WI | 603 ft | May 2 | Oct 21 |
| Belgium Wwtp, WI | 731 ft | May 5 | Oct 12 |
| Sheboygan, WI | 648 ft | Apr 25 | Oct 23 |
Frost dates near Oostburg
- Cedar Grove, WI 53013 · last May 3, first Oct 16
- Hingham, WI 53031 · last May 3, first Oct 16
- Sheboygan Falls, WI 53085 · last May 5, first Oct 8
- Kohler, WI 53044 · last Apr 25, first Oct 23
- Sheboygan, WI 53081 · last Apr 25, first Oct 23
- Belgium, WI 53004 · last May 5, first Oct 12
- Waldo, WI 53093 · last May 3, first Oct 10
- Random Lake, WI 53075 · last May 3, first Oct 16
Frequently asked questions
- When is the last frost in Oostburg, WI?
- For ZIP code 53070, the average last spring frost (32°F) is May 3, based on NOAA 1991-2020 climate normals for the Hingham Wwtp, WI weather station. There is a 1-in-10 chance of a frost after May 18.
- When is the first frost in Oostburg, WI?
- The average first fall frost (32°F) is October 16. There is a 1-in-10 chance of frost by October 2, so tender plants are at risk from that point on.
- How long is the growing season in 53070?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 165 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.