Cicero, Illinois: planting zone & frost dates
Cicero 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 17 and the first fall frost around Oct 26.
Frost dates
| Probability | Last spring frost (32°F) | First fall frost (32°F) |
|---|---|---|
| Safer (10% risk) | Apr 27 | Oct 20 |
| Typical planning date (30% risk) | Apr 17 | Oct 26 |
| Median (50%) | Apr 11 | Oct 31 |
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 CHICAGO MIDWAY AP, IL (USW00014819), 4.0 mi (6.5 km) from the city center and 7 ft higher than the city center (+2 m). Record used for the 1991–2020 normals: 23 years.
Why your yard may differ from the station: microclimates.
Hardiness zone across Cicero
All 1 ZIP code covering Cicero is in zone 6a.
ZIP codes in Cicero and their zones
| ZIP | Zone | Share of city land |
|---|---|---|
| 60804 | 6a | 100.0% |
Vegetable planting calendar for Cicero
Dates are counted from the 30%-risk frost dates above (last frost Apr 17, first frost Oct 26). Shift a week later in cold spots or low-lying ground.
| Crop | Start indoors | Transplant / plant out | Direct sow | Fall crop sow/plant |
|---|---|---|---|---|
| Tomato | Feb 20 – Mar 6 | Apr 24 – May 8 | — | — |
| Pepper | Feb 6 – Feb 20 | May 1 – May 15 | — | — |
| Lettuce | Mar 6 – Mar 20 | Apr 3 – Apr 24 | Mar 20 – May 1 | Aug 17 – Sep 14 |
| Green Beans | — | — | Apr 24 – May 29 | Aug 3 – Aug 17 |
| Sweet Corn | — | — | Apr 24 – May 22 | — |
| Zucchini & Summer Squash | Mar 20 – Mar 27 | Apr 24 – May 8 | Apr 24 – May 15 | Aug 3 – Aug 17 |
| Cucumber | Mar 20 – Mar 27 | May 1 – May 8 | Apr 24 – May 15 | Aug 3 – Aug 17 |
| Carrot | — | — | Mar 27 – May 1 | Aug 3 – Aug 17 |
| Onion | Jan 23 – Feb 6 | Mar 20 – Apr 3 | — | — |
| Potato | — | Mar 20 – Apr 10 | — | — |
| Basil | Mar 6 – Mar 20 | May 1 – May 15 | May 1 – May 22 | — |
| Spinach | — | — | Mar 6 – Apr 3 | Aug 31 – Sep 28 |
| Kale | Feb 20 – Mar 6 | Mar 20 – Apr 10 | Mar 20 – Apr 10 | Aug 17 – Sep 14 |
| Broccoli | Feb 20 – Mar 6 | Apr 3 – Apr 24 | — | Aug 3 – Aug 17 |
| Peas | — | — | Mar 6 – Mar 27 | Aug 17 – Aug 31 |
| Eggplant | Feb 6 – Feb 20 | May 1 – May 15 | — | — |
| Cabbage | Feb 20 – Mar 6 | Mar 20 – Apr 3 | — | Aug 3 – Aug 17 |
| Radish | — | — | Mar 13 – May 1 | Sep 14 – Oct 12 |
| Strawberry | — | Mar 20 – Apr 10 | — | — |
| Beets | — | — | Mar 27 – May 8 | Aug 17 – Aug 31 |
Nearby cities in Illinois
- Chicago — zone 6a, last frost Apr 17, first frost Nov 1
- Evanston — zone 6a, last frost May 2, first frost Oct 14
- Schaumburg — zone 5b, last frost May 6, first frost Oct 8
- Naperville — zone 5b, last frost May 4, first frost Oct 11
- Joliet — zone 6a, last frost Apr 26, first frost Oct 20
- Waukegan — zone 6a, last frost May 4, first frost Oct 12
More: all Illinois cities · other zone 6a cities: Chicago, IL, Denver, CO, Milwaukee, WI, Colorado Springs, CO, Omaha, NE, Aurora, CO, Lincoln, NE, Fort Wayne, IN
Cicero gardening questions
When is the last frost in Cicero, IL?
Plan around Apr 17. At NOAA's Chicago Midway Airport, IL station, 4.0 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 11, and after Apr 27 the risk drops to about 1 in 10. A hard freeze (28°F) usually ends earlier, around Apr 1. The last frost is fairly predictable here: only 28 days separate the 90% and 10% dates (median for cities on this site: 36 days).
When should I plant tomatoes in Cicero, IL?
Start seeds indoors Feb 20 – Mar 6 and set transplants outside Apr 24 – May 8, once nights stay above 50°F and the soil is near 60°F. That leaves 192 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 Cicero?
About 201 days without a 32°F frost in a typical (median) year. In 9 years out of 10 the season lasts at least 181 days, and in 1 year in 10 it runs 222 days or more. In fall there is a 10% chance of frost by Oct 20 and a 30% chance by Oct 26. That ranks 2nd longest of 14 Illinois cities on this site.
When should I plant a fall garden in Cicero?
Count back from the first fall frost (Oct 26): transplant broccoli Aug 3 – Aug 17; sow kale Aug 17 – Sep 14; sow lettuce Aug 17 – Sep 14; sow radishes Sep 14 – Oct 12. Hardy crops keep growing through light frosts; the median 28°F hard freeze here is Nov 11. How the math works: succession and fall planting.
Did Cicero's hardiness zone change on the 2023 map?
No. Going by the zone that covers most of the city's land, Cicero is zone 6a 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.
How does Cicero compare with Chicago, IL?
Both are in zone 6a. The typical last spring frost in Cicero (Apr 17) comes about the same time as in Chicago, IL (Apr 17), 4 miles away, and the first fall frost is Oct 26 versus Nov 1. The two cities use different NOAA stations.