Forest City, IL frost dates
Last spring frostApr 17median date
First fall frostOct 19median date
Growing season185 daysfrost-free
Hardiness zone6aZone 6a
How Forest City compares
- In 8 years out of 10, the last spring frost in Forest City falls between April 2 and May 3, a 31-day window. The first fall frost falls between October 1 and October 31.
- The median last frost is the same as the Illinois median of Apr 17.
- Its 185-day growing season is longer than 44% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 12 days earlier than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 133 nights a year at or below 32°F.
- Compared with Peoria, IL, 44 km away, the last frost here is 1 day later than there and the growing season is 5 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 2 |
| 50% (median) | April 17 |
| 10% (safe for tender plants) | May 3 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 1 |
| 50% (median) | October 19 |
| 90% (late) | October 31 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Forest City, IL
Forest City, IL frost dates — last frost Apr 17, first frost Oct 19, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Jan 23 to Feb 6Transplant outside: Mar 20 to Apr 3
Start indoors: Feb 6 to Feb 20Transplant outside: May 1 to May 15
Start indoors: Feb 6 to Feb 20Transplant outside: May 1 to May 15
Start indoors: Feb 20 to Mar 6Transplant outside: Apr 24 to May 8
Start indoors: Feb 20 to Mar 6Transplant outside: Mar 27 to Apr 10Sow outdoors: Mar 20 to Apr 24Plant for fall: Aug 24 to Sep 21
Start indoors: Feb 20 to Mar 6Transplant outside: Mar 20 to Apr 3Sow outdoors: Mar 20 to Apr 3Plant for fall: Aug 10 to Aug 31
Start indoors: Feb 20 to Mar 6Transplant outside: Apr 3 to Apr 17Plant for fall: Jul 13 to Aug 3
Start indoors: Feb 20 to Mar 6Transplant outside: Mar 27 to Apr 10Plant for fall: Jul 13 to Aug 3
Start indoors: Feb 20 to Mar 6Transplant outside: Apr 3 to Apr 17Plant for fall: Jul 13 to Aug 3
Start indoors: Mar 6 to Mar 20Transplant outside: May 8 to May 22Sow outdoors: May 8 to May 22
Start indoors: Mar 6 to Mar 20Transplant outside: Apr 24 to May 8
Sow outdoors: Mar 6 to Mar 27Plant for fall: Jul 27 to Aug 17
Sow outdoors: Mar 6 to Mar 27Plant for fall: Aug 24 to Sep 14
Sow outdoors: Mar 13 to Apr 24Plant for fall: Sep 7 to Sep 28
Start indoors: Mar 20 to Mar 27Transplant outside: May 1 to May 8Sow outdoors: Apr 24 to May 8Plant for fall: Aug 3 to Aug 17
Start indoors: Mar 20 to Mar 27Sow outdoors: Apr 24 to May 8Plant for fall: Aug 10 to Aug 24
Start indoors: Mar 20 to Mar 27Sow outdoors: Apr 24 to May 8
Start indoors: Mar 20 to Mar 27Transplant outside: May 1 to May 15
Sow outdoors: Mar 27 to Apr 24Plant for fall: Jul 27 to Aug 10
Sow outdoors: Mar 27 to Apr 24Plant for fall: Aug 10 to Aug 24
Sow outdoors: Mar 27 to Apr 17
Sow outdoors: Apr 3 to May 1Plant for fall: Aug 10 to Aug 24
Sow outdoors: Apr 3 to Apr 24Plant for fall: Aug 24 to Sep 14
Sow outdoors: Apr 24 to May 15Plant for fall: Aug 3 to Aug 17
Sow outdoors: Apr 24 to May 8
Transplant outside: May 1 to May 22
Plant for fall: Oct 5 to Nov 9
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Forest City, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 23 – Feb 6 | Mar 20 – Apr 3 | — | — |
| Peppers | Feb 6 – Feb 20 | May 1 – May 15 | — | — |
| Eggplant | Feb 6 – Feb 20 | May 1 – May 15 | — | — |
| Tomatoes | Feb 20 – Mar 6 | Apr 24 – May 8 | — | — |
| Lettuce | Feb 20 – Mar 6 | Mar 27 – Apr 10 | Mar 20 – Apr 24 | Aug 24 – Sep 21 |
| Kale | Feb 20 – Mar 6 | Mar 20 – Apr 3 | Mar 20 – Apr 3 | Aug 10 – Aug 31 |
| Broccoli | Feb 20 – Mar 6 | Apr 3 – Apr 17 | — | Jul 13 – Aug 3 |
| Cabbage | Feb 20 – Mar 6 | Mar 27 – Apr 10 | — | Jul 13 – Aug 3 |
| Cauliflower | Feb 20 – Mar 6 | Apr 3 – Apr 17 | — | Jul 13 – Aug 3 |
| Okra | Mar 6 – Mar 20 | May 8 – May 22 | May 8 – May 22 | — |
| Basil | Mar 6 – Mar 20 | Apr 24 – May 8 | — | — |
| Peas | — | — | Mar 6 – Mar 27 | Jul 27 – Aug 17 |
| Spinach | — | — | Mar 6 – Mar 27 | Aug 24 – Sep 14 |
| Radishes | — | — | Mar 13 – Apr 24 | Sep 7 – Sep 28 |
| Cucumbers | Mar 20 – Mar 27 | May 1 – May 8 | Apr 24 – May 8 | Aug 3 – Aug 17 |
| Zucchini & Summer Squash | Mar 20 – Mar 27 | — | Apr 24 – May 8 | Aug 10 – Aug 24 |
| Winter Squash & Pumpkins | Mar 20 – Mar 27 | — | Apr 24 – May 8 | — |
| Melons & Watermelon | Mar 20 – Mar 27 | May 1 – May 15 | — | — |
| Carrots | — | — | Mar 27 – Apr 24 | Jul 27 – Aug 10 |
| Beets | — | — | Mar 27 – Apr 24 | Aug 10 – Aug 24 |
| Potatoes | — | — | Mar 27 – Apr 17 | — |
| Swiss Chard | — | — | Apr 3 – May 1 | Aug 10 – Aug 24 |
| Cilantro | — | — | Apr 3 – Apr 24 | Aug 24 – Sep 14 |
| Green Beans | — | — | Apr 24 – May 15 | Aug 3 – Aug 17 |
| Sweet Corn | — | — | Apr 24 – May 8 | — |
| Sweet Potatoes | — | May 1 – May 22 | — | — |
| Garlic | — | — | — | Oct 5 – Nov 9 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Havana, IL weather station, 21 km away (elevation 463 ft (141 m)).
Frost dates near Forest City
- Manito Apr 17 · Oct 19
- Topeka Apr 17 · Oct 19
- San Jose Apr 17 · Oct 18
- Liverpool Apr 17 · Oct 19
- Easton Apr 17 · Oct 19
- Green Valley Apr 16 · Oct 23
- Havana Apr 17 · Oct 19
- Mason City Apr 17 · Oct 18
- South Pekin Apr 16 · Oct 23
- Dunfermline Apr 17 · Oct 19
Frequently asked questions
When is the last frost in Forest City, IL?
The median last spring frost in Forest City, IL is April 17. There is still about a 10% chance of frost after May 3, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Forest City, IL?
The median first fall frost is October 19, with about a 10% chance of frost before October 1.
How long is the growing season in Forest City, IL?
About 185 days between the median last spring frost and first fall frost.
What planting zone is Forest City, IL?
Forest City, IL is in USDA hardiness zone 6a.