Kenosha, Wisconsin: planting zone & frost dates
Kenosha is in USDA plant hardiness zone 5b, where the average coldest winter night reaches -15 to -10°F (-26.1 to -23.3°C). The typical last spring frost is around May 3 and the first fall frost around Oct 14.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | May 13 | Oct 1 |
| Typical planning date (30% risk) | May 3 | Oct 14 |
| Median (50%) | Apr 28 | Oct 19 |
How to read this: after the spring "10% risk" date, a 32°F frost happens in only about 1 year in 10. In fall, the "10% risk" date is the early end — a frost before it happens about 1 year in 10.
Frost data comes from NOAA station KENOSHA RGNL AP, WI (USW00004845), 3.0 mi (4.8 km) from the city center and 20 ft higher than the city center (+6 m). Record used for the 1991–2020 normals: 20 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Kenosha
Kenosha spans more than one half-zone. Share of the city's land area by zone (via its 5 ZIP codes): 5b (68%), 6a (32%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
Vegetable planting calendar for Kenosha
Dates are counted from the 30%-risk frost dates above (last frost May 3, first frost Oct 14). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Mar 8 – Mar 22 | May 10 – May 24 | — | — |
| Pepper | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Lettuce | Mar 22 – Apr 5 | Apr 19 – May 10 | Apr 5 – May 17 | Aug 5 – Sep 2 |
| Green Beans | — | — | May 10 – Jun 14 | Jul 22 – Aug 5 |
| Sweet Corn | — | — | May 10 – Jun 7 | — |
| Zucchini & Summer Squash | Apr 5 – Apr 12 | May 10 – May 24 | May 10 – May 31 | Jul 22 – Aug 5 |
| Cucumber | Apr 5 – Apr 12 | May 17 – May 24 | May 10 – May 31 | Jul 22 – Aug 5 |
| Carrot | — | — | Apr 12 – May 17 | Jul 22 – Aug 5 |
| Onion | Feb 8 – Feb 22 | Apr 5 – Apr 19 | — | — |
| Potato | — | Apr 5 – Apr 26 | — | — |
| Basil | Mar 22 – Apr 5 | May 17 – May 31 | May 17 – Jun 7 | — |
| Spinach | — | — | Mar 22 – Apr 19 | Aug 19 – Sep 16 |
| Kale | Mar 8 – Mar 22 | Apr 5 – Apr 26 | Apr 5 – Apr 26 | Aug 5 – Sep 2 |
| Broccoli | Mar 8 – Mar 22 | Apr 19 – May 10 | — | Jul 22 – Aug 5 |
| Peas | — | — | Mar 22 – Apr 12 | Aug 5 – Aug 19 |
| Eggplant | Feb 22 – Mar 8 | May 17 – May 31 | — | — |
| Cabbage | Mar 8 – Mar 22 | Apr 5 – Apr 19 | — | Jul 22 – Aug 5 |
| Radish | — | — | Mar 29 – May 17 | Sep 2 – Sep 30 |
| Strawberry | — | Apr 5 – Apr 26 | — | — |
| Beets | — | — | Apr 12 – May 24 | Aug 5 – Aug 19 |
Nearby cities in Wisconsin
- Racine — zone 6a, last frost Apr 27, first frost Oct 18
- Milwaukee — zone 6a, last frost May 2, first frost Oct 12
- Madison — zone 5b, last frost May 7, first frost Oct 3
- Green Bay — zone 5b, last frost May 13, first frost Oct 2
More: all Wisconsin cities · other zone 5b cities: Madison, WI, Des Moines, IA, Aurora, IL, Fort Collins, CO, Naperville, IL, Rockford, IL, Elgin, IL, Greeley, CO
Kenosha gardening questions
When is the last frost in Kenosha, WI?
Plan around May 3. At NOAA's Kenosha Regional Airport, WI station, 3.0 mi from the city center, there is a 30% chance of a 32°F frost after that date. Half of springs have their last frost by Apr 28, and after May 13 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 15. The 90% and 10% dates are 30 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Kenosha, WI?
Start seeds indoors Mar 8 – Mar 22 and set transplants outside May 10 – May 24, once nights stay above 50°F and the soil is near 60°F. That leaves 164 days between the 30% frost dates, enough for most varieties including 80–85-day slicers. More: tomato planting dates by zone.
How long is the growing season in Kenosha?
About 174 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 153 days, and in 1 year in 10 it runs 194 days or more. In fall there is a 10% chance of frost by Oct 1 and a 30% chance by Oct 14. That ranks 2nd longest of 5 Wisconsin cities on this site.
When should I plant a fall garden in Kenosha?
Count back from the first fall frost (Oct 14): transplant broccoli Jul 22 – Aug 5; sow kale Aug 5 – Sep 2; sow lettuce Aug 5 – Sep 2; sow radishes Sep 2 – Sep 30. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Oct 30. How the math works: succession and fall planting.
Did Kenosha's hardiness zone change on the 2023 map?
No. Going by the zone that covers most of the city's land, Kenosha is zone 5b on both the 2012 and the 2023 USDA maps (PRISM/OSU ZIP listings). About 42% of U.S. ZIP codes kept their half-zone in 2023. Why the 2023 map is warmer.
Is all of Kenosha in zone 5b?
No. Zone 5b covers about 68% of the city's land; the rest is in 6a (32%), measured across the city's 5 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.