Milwaukee, WI planting zone & frost dates
Milwaukee is in USDA hardiness zone 6a. The last spring frost usually comes around April 26 and the first fall frost around October 22, for a growing season of about 177 days.
Planting calendar for Milwaukee
Dates are counted from the average last spring frost (April 26) using the typical timing recommended by U.S. extension services. Warm-season crops go out only after the danger of frost has passed and the soil has warmed.
| Crop | When |
|---|---|
| Tomatoes | Start seeds indoors: Mar 1 – Mar 15 Transplant outdoors: May 3 – May 10 |
| Peppers | Start seeds indoors: Feb 15 – Mar 1 Transplant outdoors: May 10 – May 17 |
| Eggplant | Start seeds indoors: Feb 15 – Mar 1 Transplant outdoors: May 10 – May 17 |
| Broccoli | Start seeds indoors: Feb 15 – Mar 1 Transplant outdoors: Mar 29 – Apr 12 |
| Cabbage | Start seeds indoors: Feb 15 – Mar 1 Transplant outdoors: Mar 29 – Apr 12 |
| Onions (sets) | Plant outdoors: Mar 29 – Apr 12 |
| Peas | Sow outdoors: Mar 15 – Mar 29 |
| Spinach | Sow outdoors: Mar 15 – Mar 29 |
| Lettuce | Sow outdoors: Mar 29 – Apr 12 |
| Carrots | Sow outdoors: Mar 29 – Apr 12 |
| Potatoes | Plant outdoors: Mar 29 – Apr 12 |
| Beans | Sow outdoors: May 3 – May 10 |
| Sweet corn | Sow outdoors: May 3 – May 10 |
| Cucumbers | Sow outdoors: May 3 – May 10 |
| Squash & zucchini | Sow outdoors: May 3 – May 10 |
| Basil | Start seeds indoors: Mar 15 – Mar 29 Transplant outdoors: May 3 – May 10 |
Fall garden: cool-season crops like lettuce, spinach and kale can be sown again around Aug 27 (8 weeks before the average first fall frost on Oct 22).
Useful for zone 6a gardens
- Seed starting kit with dome — to start seeds indoors before the last frost
- LED grow light for seedlings — stops leggy seedlings
- Frost cloth / plant covers — for late spring and early fall frosts
- Soil thermometer — warm-season crops need soil above 60°F
- Cold frame / mini greenhouse — adds weeks to a short season
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Frost risk in detail
| 90% chance | 50% chance | 10% chance | |
|---|---|---|---|
| Last 32°F frost in spring is after | Apr 12 | Apr 26 | May 12 |
| First 32°F frost in fall is before | Nov 3 | Oct 22 | Oct 7 |
How to read it: in spring there is a 10% chance of a frost after May 12, so that is a safe date for tender plants. In fall there is a 10% chance of frost before October 7. A hard freeze (28°F) usually ends around April 14.
Hardiness zone by ZIP code in Milwaukee
- 53201 zone 6a
- 53202 zone 6a
- 53203 zone 6a
- 53204 zone 6a
- 53205 zone 6a
- 53206 zone 6a
- 53207 zone 6a
- 53208 zone 6a
- 53209 zone 6a
- 53210 zone 6a
- 53211 zone 6a
- 53212 zone 6a
- 53213 zone 5b
- 53214 zone 5b
- 53215 zone 6a
- 53216 zone 6a
- 53217 zone 6a
- 53218 zone 6a
- 53219 zone 5b
- 53220 zone 5b
- 53221 zone 6a
- 53222 zone 5b
- 53223 zone 6a
- 53224 zone 5b
- 53225 zone 5b
- 53226 zone 5b
- 53227 zone 5b
- 53228 zone 5b
- 53233 zone 6a
- 53234 zone 6a
- 53237 zone 6a
- 53259 zone 6a
- 53263 zone 5b
- 53274 zone 6a
- 53278 zone 6a
- 53288 zone 6a
- 53290 zone 6a
- 53293 zone 6a
- 53295 zone 6a
Nearby cities
- Shorewood zone 6a, last frost Apr 26
- Whitefish Bay zone 6a, last frost Apr 26
- Cudahy zone 6a, last frost Apr 19
- Glendale zone 6a, last frost Apr 26
- Wauwatosa zone 5b, last frost Apr 26
- West Allis zone 5b, last frost Apr 26
- Greenfield zone 5b, last frost May 3
- Greendale zone 5b, last frost May 3
Questions
What growing zone is Milwaukee, WI?
Milwaukee is in USDA Plant Hardiness Zone 6a (average extreme winter low -10°F to -5°F), according to the USDA 2023 map. Some ZIP codes of the city fall in zone 5b.
When is the last frost in Milwaukee?
The average last spring frost (32°F) in Milwaukee is April 26. There is still a 10% chance of frost until May 12.
When can I plant tomatoes in Milwaukee?
Transplant tomatoes outdoors 1–2 weeks after the average last frost: around May 3 – May 10. Start seeds indoors 6–8 weeks before the last frost.
Frost dates: NOAA U.S. Climate Normals 1991–2020, station West Allis, WI (USC00479046), 8.1 km (5.0 mi) from the city center, elevation 220 m, based on 11 years of records. Hardiness zone: USDA Plant Hardiness Zone Map 2023 for the ZIP code nearest to the city center. Microclimates (valleys, hills, cities, coasts) can be warmer or colder: check the local forecast before planting. How we calculate the data.