Frost dates for 53074Port Washington, WI
The average last spring frost in Port Washington is April 27 and the average first fall frost is October 22, giving a typical growing season of about 176 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 27
- Average first fall frost
- Oct 22
- Growing season
- 176 days
Safer after May 14 (1-in-10 risk)
Possible by Oct 6 (1-in-10 risk)
Last frost typically in 182 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 26 · May 10 · May 25 | Sep 26 · Oct 10 · Oct 24 | 153 days | 100% |
| Frost / freeze (32°F) | Apr 11 · Apr 27 · May 14 | Oct 6 · Oct 22 · Nov 4 | 176 days | 100% |
| Hard freeze (28°F) | Mar 31 · Apr 13 · Apr 30 | Oct 19 · Nov 2 · Nov 17 | 202 days | 100% |
Planting calendar for Port Washington
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 27 – Jun 2 |
| Tomatoes | Transplant outdoors | May 13 – Jul 2 |
| Peppers | Start seeds indoors | Mar 27 – Apr 27 |
| Peppers | Transplant outdoors | May 27 – Jun 27 |
| Eggplant | Start seeds indoors | Apr 13 – May 12 |
| Eggplant | Transplant outdoors | May 27 – Jun 27 |
| Cucumbers | Sow outdoors | May 27 – Jul 12 |
| Summer squash | Sow outdoors | May 13 – Jun 27 |
| Winter squash & pumpkins | Sow outdoors | May 27 – Jun 27 |
| Snap beans | Sow outdoors | May 13 – Aug 4 |
| Sweet corn | Sow outdoors | May 13 – Jul 2 |
| Watermelon & cantaloupe | Sow outdoors | May 27 – Jun 27 |
| Okra | Sow outdoors | May 20 – Jun 12 |
| Peas | Sow outdoors (spring) | Mar 27 – May 12 |
| Potatoes | Plant outdoors (spring) | Mar 27 – May 27 |
| Onions | Start seeds indoors (spring) | Feb 13 – Mar 12 |
| Onions | Transplant outdoors (spring) | Apr 13 – May 12 |
| Broccoli | Start seeds indoors (spring) | Mar 9 – Apr 12 |
| Broccoli | Transplant outdoors (spring) | Apr 13 – May 12 |
| Broccoli | Start seeds indoors (fall) | Jun 22 – Jul 2 |
| Broccoli | Transplant outdoors (fall) | Jul 22 – Aug 2 |
| Cabbage | Start seeds indoors (spring) | Feb 27 – Mar 27 |
| Cabbage | Transplant outdoors (spring) | Mar 27 – Apr 27 |
| Cabbage | Start seeds indoors (fall) | Jun 12 – Jul 12 |
| Cabbage | Transplant outdoors (fall) | Jul 12 – Aug 12 |
| Leaf lettuce | Sow outdoors (spring) | Mar 27 – Jun 12 |
| Leaf lettuce | Sow outdoors (fall) | Jul 12 – Aug 28 |
| Spinach | Sow outdoors (spring) | Mar 20 – May 3 |
| Spinach | Sow outdoors (fall) | Jul 29 – Sep 2 |
| Radishes | Sow outdoors (spring) | Mar 27 – May 17 |
| Radishes | Sow outdoors (fall) | Jul 12 – Sep 12 |
| Kale | Sow outdoors (spring) | Apr 13 – May 3 |
| Kale | Sow outdoors (fall) | Jul 5 – Aug 12 |
| Carrots | Sow outdoors (spring) | Apr 27 – Jun 12 |
| Carrots | Sow outdoors (fall) | Jun 12 – Jul 28 |
| Garlic | Plant outdoors (fall) | Oct 12 – Nov 12 |
Where these dates come from
ZIP code 53074 is matched to the NOAA station Port Washington, WI, 1.3 km away, at 594 ft elevation (75 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Port Washington, WI (used) | 594 ft | Apr 27 | Oct 22 |
| Saukville Wwtp, WI | 766 ft | May 5 | Oct 11 |
| Grafton Wwtp, WI | 741 ft | Apr 23 | Oct 24 |
| Belgium Wwtp, WI | 731 ft | May 5 | Oct 12 |
Frost dates near Port Washington
- Saukville, WI 53080 · last Apr 27, first Oct 22
- Grafton, WI 53024 · last Apr 23, first Oct 24
- Fredonia, WI 53021 · last May 3, first Oct 16
- Belgium, WI 53004 · last May 5, first Oct 12
- Cedarburg, WI 53012 · last May 6, first Oct 8
- Newburg, WI 53060 · last May 4, first Oct 11
- Mequon, WI 53097 · last May 6, first Oct 8
- Cedar Grove, WI 53013 · last May 3, first Oct 16
Frequently asked questions
- When is the last frost in Port Washington, WI?
- For ZIP code 53074, the average last spring frost (32°F) is April 27, based on NOAA 1991-2020 climate normals for the Port Washington, WI weather station. There is a 1-in-10 chance of a frost after May 14.
- When is the first frost in Port Washington, WI?
- The average first fall frost (32°F) is October 22. There is a 1-in-10 chance of frost by October 6, so tender plants are at risk from that point on.
- How long is the growing season in 53074?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 176 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.