Frost dates for 53221Milwaukee, WI
The average last spring frost in Milwaukee is April 19 and the average first fall frost is October 29, giving a typical growing season of about 192 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 19
- Average first fall frost
- Oct 29
- Growing season
- 192 days
Safer after May 2 (1-in-10 risk)
Possible by Oct 15 (1-in-10 risk)
First frost typically in 3 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 18 · May 1 · May 15 | Oct 5 · Oct 18 · Oct 30 | 168 days | 100% |
| Frost / freeze (32°F) | Apr 6 · Apr 19 · May 2 | Oct 15 · Oct 29 · Nov 10 | 192 days | 100% |
| Hard freeze (28°F) | Mar 24 · Apr 6 · Apr 20 | Oct 27 · Nov 8 · Nov 22 | 215 days | 100% |
Planting calendar for Milwaukee
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 19 – May 25 |
| Tomatoes | Transplant outdoors | May 5 – Jul 9 |
| Peppers | Start seeds indoors | Mar 19 – Apr 19 |
| Peppers | Transplant outdoors | May 19 – Jun 19 |
| Eggplant | Start seeds indoors | Apr 5 – May 4 |
| Eggplant | Transplant outdoors | May 19 – Jun 19 |
| Cucumbers | Sow outdoors | May 19 – Jul 19 |
| Summer squash | Sow outdoors | May 5 – Jun 19 |
| Winter squash & pumpkins | Sow outdoors | May 19 – Jun 19 |
| Snap beans | Sow outdoors | May 5 – Aug 11 |
| Sweet corn | Sow outdoors | May 5 – Jul 9 |
| Watermelon & cantaloupe | Sow outdoors | May 19 – Jun 19 |
| Okra | Sow outdoors | May 12 – Jun 4 |
| Peas | Sow outdoors (spring) | Mar 19 – May 4 |
| Potatoes | Plant outdoors (spring) | Mar 19 – May 19 |
| Onions | Start seeds indoors (spring) | Feb 5 – Mar 4 |
| Onions | Transplant outdoors (spring) | Apr 5 – May 4 |
| Broccoli | Start seeds indoors (spring) | Mar 1 – Apr 4 |
| Broccoli | Transplant outdoors (spring) | Apr 5 – May 4 |
| Broccoli | Start seeds indoors (fall) | Jun 29 – Jul 9 |
| Broccoli | Transplant outdoors (fall) | Jul 29 – Aug 9 |
| Cabbage | Start seeds indoors (spring) | Feb 19 – Mar 19 |
| Cabbage | Transplant outdoors (spring) | Mar 19 – Apr 19 |
| Cabbage | Start seeds indoors (fall) | Jun 19 – Jul 19 |
| Cabbage | Transplant outdoors (fall) | Jul 19 – Aug 19 |
| Leaf lettuce | Sow outdoors (spring) | Mar 19 – Jun 4 |
| Leaf lettuce | Sow outdoors (fall) | Jul 19 – Sep 4 |
| Spinach | Sow outdoors (spring) | Mar 12 – Apr 25 |
| Spinach | Sow outdoors (fall) | Aug 5 – Sep 9 |
| Radishes | Sow outdoors (spring) | Mar 19 – May 9 |
| Radishes | Sow outdoors (fall) | Jul 19 – Sep 19 |
| Kale | Sow outdoors (spring) | Apr 5 – Apr 25 |
| Kale | Sow outdoors (fall) | Jul 12 – Aug 19 |
| Carrots | Sow outdoors (spring) | Apr 19 – Jun 4 |
| Carrots | Sow outdoors (fall) | Jun 19 – Aug 4 |
| Garlic | Plant outdoors (fall) | Oct 19 – Nov 19 |
Where these dates come from
ZIP code 53221 is matched to the NOAA station Milwaukee Mitchell Ap, WI, 3.3 km away, at 670 ft elevation (72 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Milwaukee Mitchell Ap, WI (used) | 670 ft | Apr 19 | Oct 29 |
| Hales Corners/Whitnall Park/Bo, WI | 774 ft | May 3 | Oct 14 |
| West Allis, WI | 723 ft | Apr 26 | Oct 22 |
| South Milwaukee Wwtp, WI | 650 ft | Apr 22 | Oct 26 |
Frost dates near Milwaukee
- Milwaukee, WI 53220 · last Apr 19, first Oct 29
- Greendale, WI 53129 · last Apr 19, first Oct 29
- Saint Francis, WI 53235 · last Apr 19, first Oct 29
- Cudahy, WI 53110 · last Apr 19, first Oct 29
- Franklin, WI 53132 · last Apr 19, first Oct 29
- Oak Creek, WI 53154 · last Apr 19, first Oct 29
- South Milwaukee, WI 53172 · last Apr 19, first Oct 29
- Hales Corners, WI 53130 · last May 3, first Oct 14
Frequently asked questions
- When is the last frost in Milwaukee, WI?
- For ZIP code 53221, the average last spring frost (32°F) is April 19, based on NOAA 1991-2020 climate normals for the Milwaukee Mitchell Ap, WI weather station. There is a 1-in-10 chance of a frost after May 2.
- When is the first frost in Milwaukee, WI?
- The average first fall frost (32°F) is October 29. There is a 1-in-10 chance of frost by October 15, so tender plants are at risk from that point on.
- How long is the growing season in 53221?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 192 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.