Windsor, IL frost dates
Last spring frostApr 16median date
First fall frostOct 22median date
Growing season189 daysfrost-free
Hardiness zone6aZone 6a
How Windsor compares
- In 8 years out of 10, the last spring frost in Windsor falls between April 3 and April 30, a 27-day window. The first fall frost falls between October 8 and November 2.
- The median last frost is 1 day earlier than the Illinois median of Apr 17.
- Its 189-day growing season is longer than 54% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 13 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 109 nights a year at or below 32°F.
- Compared with Decatur, IL, 57 km away, the last frost here is 2 days later than there and the growing season is 4 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 3 |
| 50% (median) | April 16 |
| 10% (safe for tender plants) | April 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 8 |
| 50% (median) | October 22 |
| 90% (late) | November 2 |
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 Windsor, IL
Windsor, IL frost dates — last frost Apr 16, first frost Oct 22, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Jan 22 to Feb 5Transplant outside: Mar 19 to Apr 2
Start indoors: Feb 5 to Feb 19Transplant outside: Apr 30 to May 14
Start indoors: Feb 5 to Feb 19Transplant outside: Apr 30 to May 14
Start indoors: Feb 19 to Mar 5Transplant outside: Apr 23 to May 7
Start indoors: Feb 19 to Mar 5Transplant outside: Mar 26 to Apr 9Sow outdoors: Mar 19 to Apr 23Plant for fall: Aug 27 to Sep 24
Start indoors: Feb 19 to Mar 5Transplant outside: Mar 19 to Apr 2Sow outdoors: Mar 19 to Apr 2Plant for fall: Aug 13 to Sep 3
Start indoors: Feb 19 to Mar 5Transplant outside: Apr 2 to Apr 16Plant for fall: Jul 16 to Aug 6
Start indoors: Feb 19 to Mar 5Transplant outside: Mar 26 to Apr 9Plant for fall: Jul 16 to Aug 6
Start indoors: Feb 19 to Mar 5Transplant outside: Apr 2 to Apr 16Plant for fall: Jul 16 to Aug 6
Start indoors: Mar 5 to Mar 19Transplant outside: May 7 to May 21Sow outdoors: May 7 to May 21
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 23 to May 7
Sow outdoors: Mar 5 to Mar 26Plant for fall: Jul 30 to Aug 20
Sow outdoors: Mar 5 to Mar 26Plant for fall: Aug 27 to Sep 17
Sow outdoors: Mar 12 to Apr 23Plant for fall: Sep 10 to Oct 1
Start indoors: Mar 19 to Mar 26Transplant outside: Apr 30 to May 7Sow outdoors: Apr 23 to May 7Plant for fall: Aug 6 to Aug 20
Start indoors: Mar 19 to Mar 26Sow outdoors: Apr 23 to May 7Plant for fall: Aug 13 to Aug 27
Start indoors: Mar 19 to Mar 26Sow outdoors: Apr 23 to May 7
Start indoors: Mar 19 to Mar 26Transplant outside: Apr 30 to May 14
Sow outdoors: Mar 26 to Apr 23Plant for fall: Jul 30 to Aug 13
Sow outdoors: Mar 26 to Apr 23Plant for fall: Aug 13 to Aug 27
Sow outdoors: Mar 26 to Apr 16
Sow outdoors: Apr 2 to Apr 30Plant for fall: Aug 13 to Aug 27
Sow outdoors: Apr 2 to Apr 23Plant for fall: Aug 27 to Sep 17
Sow outdoors: Apr 23 to May 14Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 23 to May 7
Transplant outside: Apr 30 to May 21
Plant for fall: Oct 8 to Nov 12
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Windsor, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 22 – Feb 5 | Mar 19 – Apr 2 | — | — |
| Peppers | Feb 5 – Feb 19 | Apr 30 – May 14 | — | — |
| Eggplant | Feb 5 – Feb 19 | Apr 30 – May 14 | — | — |
| Tomatoes | Feb 19 – Mar 5 | Apr 23 – May 7 | — | — |
| Lettuce | Feb 19 – Mar 5 | Mar 26 – Apr 9 | Mar 19 – Apr 23 | Aug 27 – Sep 24 |
| Kale | Feb 19 – Mar 5 | Mar 19 – Apr 2 | Mar 19 – Apr 2 | Aug 13 – Sep 3 |
| Broccoli | Feb 19 – Mar 5 | Apr 2 – Apr 16 | — | Jul 16 – Aug 6 |
| Cabbage | Feb 19 – Mar 5 | Mar 26 – Apr 9 | — | Jul 16 – Aug 6 |
| Cauliflower | Feb 19 – Mar 5 | Apr 2 – Apr 16 | — | Jul 16 – Aug 6 |
| Okra | Mar 5 – Mar 19 | May 7 – May 21 | May 7 – May 21 | — |
| Basil | Mar 5 – Mar 19 | Apr 23 – May 7 | — | — |
| Peas | — | — | Mar 5 – Mar 26 | Jul 30 – Aug 20 |
| Spinach | — | — | Mar 5 – Mar 26 | Aug 27 – Sep 17 |
| Radishes | — | — | Mar 12 – Apr 23 | Sep 10 – Oct 1 |
| Cucumbers | Mar 19 – Mar 26 | Apr 30 – May 7 | Apr 23 – May 7 | Aug 6 – Aug 20 |
| Zucchini & Summer Squash | Mar 19 – Mar 26 | — | Apr 23 – May 7 | Aug 13 – Aug 27 |
| Winter Squash & Pumpkins | Mar 19 – Mar 26 | — | Apr 23 – May 7 | — |
| Melons & Watermelon | Mar 19 – Mar 26 | Apr 30 – May 14 | — | — |
| Carrots | — | — | Mar 26 – Apr 23 | Jul 30 – Aug 13 |
| Beets | — | — | Mar 26 – Apr 23 | Aug 13 – Aug 27 |
| Potatoes | — | — | Mar 26 – Apr 16 | — |
| Swiss Chard | — | — | Apr 2 – Apr 30 | Aug 13 – Aug 27 |
| Cilantro | — | — | Apr 2 – Apr 23 | Aug 27 – Sep 17 |
| Green Beans | — | — | Apr 23 – May 14 | Aug 6 – Aug 20 |
| Sweet Corn | — | — | Apr 23 – May 7 | — |
| Sweet Potatoes | — | Apr 30 – May 21 | — | — |
| Garlic | — | — | — | Oct 8 – Nov 12 |
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 Windsor, IL weather station, 2 km away (elevation 689 ft (210 m)).
Frost dates near Windsor
- Gays Apr 16 · Oct 22
- Strasburg Apr 16 · Oct 22
- Neoga Apr 16 · Oct 20
- Findlay Apr 10 · Oct 24
- Stewardson Apr 16 · Oct 20
- Sullivan Apr 15 · Oct 22
- Mattoon Apr 11 · Oct 29
- Shelbyville Apr 10 · Oct 24
- Trilla Apr 11 · Oct 29
- Mode Apr 10 · Oct 24
Frequently asked questions
When is the last frost in Windsor, IL?
The median last spring frost in Windsor, IL is April 16. There is still about a 10% chance of frost after April 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Windsor, IL?
The median first fall frost is October 22, with about a 10% chance of frost before October 8.
How long is the growing season in Windsor, IL?
About 189 days between the median last spring frost and first fall frost.
What planting zone is Windsor, IL?
Windsor, IL is in USDA hardiness zone 6a.