Racine, Wisconsin: planting zone & frost dates
Racine is in USDA plant hardiness zone 6a, where the average coldest winter night reaches -10 to -5°F (-23.3 to -20.6°C). The typical last spring frost is around Apr 27 and the first fall frost around Oct 18.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | May 6 | Oct 8 |
| Typical planning date (30% risk) | Apr 27 | Oct 18 |
| Median (50%) | Apr 20 | Oct 24 |
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 RACINE, WI (USC00476922), 2.2 mi (3.5 km) from the city center and 49 ft lower than the city center (-15 m). Record used for the 1991–2020 normals: 29 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Racine
Racine spans more than one half-zone. Share of the city's land area by zone (via its 5 ZIP codes): 6a (84%), 5b (16%). The headline zone is the one covering the most land. Look up your ZIP for your exact zone.
Vegetable planting calendar for Racine
Dates are counted from the 30%-risk frost dates above (last frost Apr 27, first frost Oct 18). 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 2 – Mar 16 | May 4 – May 18 | — | — |
| Pepper | Feb 16 – Mar 2 | May 11 – May 25 | — | — |
| Lettuce | Mar 16 – Mar 30 | Apr 13 – May 4 | Mar 30 – May 11 | Aug 9 – Sep 6 |
| Green Beans | — | — | May 4 – Jun 8 | Jul 26 – Aug 9 |
| Sweet Corn | — | — | May 4 – Jun 1 | — |
| Zucchini & Summer Squash | Mar 30 – Apr 6 | May 4 – May 18 | May 4 – May 25 | Jul 26 – Aug 9 |
| Cucumber | Mar 30 – Apr 6 | May 11 – May 18 | May 4 – May 25 | Jul 26 – Aug 9 |
| Carrot | — | — | Apr 6 – May 11 | Jul 26 – Aug 9 |
| Onion | Feb 2 – Feb 16 | Mar 30 – Apr 13 | — | — |
| Potato | — | Mar 30 – Apr 20 | — | — |
| Basil | Mar 16 – Mar 30 | May 11 – May 25 | May 11 – Jun 1 | — |
| Spinach | — | — | Mar 16 – Apr 13 | Aug 23 – Sep 20 |
| Kale | Mar 2 – Mar 16 | Mar 30 – Apr 20 | Mar 30 – Apr 20 | Aug 9 – Sep 6 |
| Broccoli | Mar 2 – Mar 16 | Apr 13 – May 4 | — | Jul 26 – Aug 9 |
| Peas | — | — | Mar 16 – Apr 6 | Aug 9 – Aug 23 |
| Eggplant | Feb 16 – Mar 2 | May 11 – May 25 | — | — |
| Cabbage | Mar 2 – Mar 16 | Mar 30 – Apr 13 | — | Jul 26 – Aug 9 |
| Radish | — | — | Mar 23 – May 11 | Sep 6 – Oct 4 |
| Strawberry | — | Mar 30 – Apr 20 | — | — |
| Beets | — | — | Apr 6 – May 18 | Aug 9 – Aug 23 |
Nearby cities in Wisconsin
- Kenosha — zone 5b, last frost May 3, first frost Oct 14
- 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 6a cities: Chicago, IL, Denver, CO, Milwaukee, WI, Colorado Springs, CO, Omaha, NE, Aurora, CO, Lincoln, NE, Fort Wayne, IN
Racine gardening questions
When is the last frost in Racine, WI?
Plan around Apr 27. At NOAA's Racine, WI station, 2.2 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 20, and after May 6 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 9. The 90% and 10% dates are 29 days apart, close to the 36-day median for cities on this site.
When should I plant tomatoes in Racine, WI?
Start seeds indoors Mar 2 – Mar 16 and set transplants outside May 4 – May 18, once nights stay above 50°F and the soil is near 60°F. That leaves 174 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 Racine?
About 184 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 162 days, and in 1 year in 10 it runs 203 days or more. In fall there is a 10% chance of frost by Oct 8 and a 30% chance by Oct 18. That is the longest of the 5 Wisconsin cities on this site.
When should I plant a fall garden in Racine?
Count back from the first fall frost (Oct 18): transplant broccoli Jul 26 – Aug 9; sow kale Aug 9 – Sep 6; sow lettuce Aug 9 – Sep 6; sow radishes Sep 6 – Oct 4. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 3. How the math works: succession and fall planting.
Did Racine's hardiness zone change on the 2023 map?
Yes. Most of Racine was zone 5b on the 2012 map and is zone 6a on the 2023 map — half a zone warmer, like about 56% of U.S. ZIP codes. The shift comes from a newer 1991–2020 averaging period plus more weather stations and better mapping; it does not mean last frost comes earlier. Why the 2023 map is warmer.
Is all of Racine in zone 6a?
No. Zone 6a covers about 84% of the city's land; the rest is in 5b (16%), measured across the city's 5 ZIP codes. Check your own ZIP code in the table above or with the ZIP lookup.