Frost dates for 62521 — Decatur, IL
Last spring frostApr 14median date
First fall frostOct 24median date
Growing season193 daysfrost-free
Hardiness zone6aZone 6a
How Decatur compares
- In 8 years out of 10, the last spring frost in Decatur falls between April 1 and May 1, a 30-day window. The first fall frost falls between October 11 and November 5.
- The median last frost is 3 days earlier than the Illinois median of Apr 17.
- Its 193-day growing season is longer than 70% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 15 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 110 nights a year at or below 32°F.
- Compared with Springfield, IL, 58 km away, the last frost here is 1 day earlier than there and the growing season is 3 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 1 |
| 50% (median) | April 14 |
| 10% (safe for tender plants) | May 1 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 11 |
| 50% (median) | October 24 |
| 90% (late) | November 5 |
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 Decatur, IL
Frost dates for 62521 — Decatur, IL — last frost Apr 14, first frost Oct 24, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Jan 20 to Feb 3Transplant outside: Mar 17 to Mar 31
Start indoors: Feb 3 to Feb 17Transplant outside: Apr 28 to May 12
Start indoors: Feb 3 to Feb 17Transplant outside: Apr 28 to May 12
Start indoors: Feb 17 to Mar 3Transplant outside: Apr 21 to May 5
Start indoors: Feb 17 to Mar 3Transplant outside: Mar 24 to Apr 7Sow outdoors: Mar 17 to Apr 21Plant for fall: Aug 29 to Sep 26
Start indoors: Feb 17 to Mar 3Transplant outside: Mar 17 to Mar 31Sow outdoors: Mar 17 to Mar 31Plant for fall: Aug 15 to Sep 5
Start indoors: Feb 17 to Mar 3Transplant outside: Mar 31 to Apr 14Plant for fall: Jul 18 to Aug 8
Start indoors: Feb 17 to Mar 3Transplant outside: Mar 24 to Apr 7Plant for fall: Jul 18 to Aug 8
Start indoors: Feb 17 to Mar 3Transplant outside: Mar 31 to Apr 14Plant for fall: Jul 18 to Aug 8
Start indoors: Mar 3 to Mar 17Transplant outside: May 5 to May 19Sow outdoors: May 5 to May 19
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 21 to May 5
Sow outdoors: Mar 3 to Mar 24Plant for fall: Aug 1 to Aug 22
Sow outdoors: Mar 3 to Mar 24Plant for fall: Aug 29 to Sep 19
Sow outdoors: Mar 10 to Apr 21Plant for fall: Sep 12 to Oct 3
Start indoors: Mar 17 to Mar 24Transplant outside: Apr 28 to May 5Sow outdoors: Apr 21 to May 5Plant for fall: Aug 8 to Aug 22
Start indoors: Mar 17 to Mar 24Sow outdoors: Apr 21 to May 5Plant for fall: Aug 15 to Aug 29
Start indoors: Mar 17 to Mar 24Sow outdoors: Apr 21 to May 5
Start indoors: Mar 17 to Mar 24Transplant outside: Apr 28 to May 12
Sow outdoors: Mar 24 to Apr 21Plant for fall: Aug 1 to Aug 15
Sow outdoors: Mar 24 to Apr 21Plant for fall: Aug 15 to Aug 29
Sow outdoors: Mar 24 to Apr 14
Sow outdoors: Mar 31 to Apr 28Plant for fall: Aug 15 to Aug 29
Sow outdoors: Mar 31 to Apr 21Plant for fall: Aug 29 to Sep 19
Sow outdoors: Apr 21 to May 12Plant for fall: Aug 8 to Aug 22
Sow outdoors: Apr 21 to May 5
Transplant outside: Apr 28 to May 19
Plant for fall: Oct 10 to Nov 14
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Decatur, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 20 – Feb 3 | Mar 17 – Mar 31 | — | — |
| Peppers | Feb 3 – Feb 17 | Apr 28 – May 12 | — | — |
| Eggplant | Feb 3 – Feb 17 | Apr 28 – May 12 | — | — |
| Tomatoes | Feb 17 – Mar 3 | Apr 21 – May 5 | — | — |
| Lettuce | Feb 17 – Mar 3 | Mar 24 – Apr 7 | Mar 17 – Apr 21 | Aug 29 – Sep 26 |
| Kale | Feb 17 – Mar 3 | Mar 17 – Mar 31 | Mar 17 – Mar 31 | Aug 15 – Sep 5 |
| Broccoli | Feb 17 – Mar 3 | Mar 31 – Apr 14 | — | Jul 18 – Aug 8 |
| Cabbage | Feb 17 – Mar 3 | Mar 24 – Apr 7 | — | Jul 18 – Aug 8 |
| Cauliflower | Feb 17 – Mar 3 | Mar 31 – Apr 14 | — | Jul 18 – Aug 8 |
| Okra | Mar 3 – Mar 17 | May 5 – May 19 | May 5 – May 19 | — |
| Basil | Mar 3 – Mar 17 | Apr 21 – May 5 | — | — |
| Peas | — | — | Mar 3 – Mar 24 | Aug 1 – Aug 22 |
| Spinach | — | — | Mar 3 – Mar 24 | Aug 29 – Sep 19 |
| Radishes | — | — | Mar 10 – Apr 21 | Sep 12 – Oct 3 |
| Cucumbers | Mar 17 – Mar 24 | Apr 28 – May 5 | Apr 21 – May 5 | Aug 8 – Aug 22 |
| Zucchini & Summer Squash | Mar 17 – Mar 24 | — | Apr 21 – May 5 | Aug 15 – Aug 29 |
| Winter Squash & Pumpkins | Mar 17 – Mar 24 | — | Apr 21 – May 5 | — |
| Melons & Watermelon | Mar 17 – Mar 24 | Apr 28 – May 12 | — | — |
| Carrots | — | — | Mar 24 – Apr 21 | Aug 1 – Aug 15 |
| Beets | — | — | Mar 24 – Apr 21 | Aug 15 – Aug 29 |
| Potatoes | — | — | Mar 24 – Apr 14 | — |
| Swiss Chard | — | — | Mar 31 – Apr 28 | Aug 15 – Aug 29 |
| Cilantro | — | — | Mar 31 – Apr 21 | Aug 29 – Sep 19 |
| Green Beans | — | — | Apr 21 – May 12 | Aug 8 – Aug 22 |
| Sweet Corn | — | — | Apr 21 – May 5 | — |
| Sweet Potatoes | — | Apr 28 – May 19 | — | — |
| Garlic | — | — | — | Oct 10 – Nov 14 |
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 Decatur Wtp, IL weather station, about 1 km away (elevation 640 ft (195 m)).
ZIP codes in Decatur: 62521 62522 62523 62524 62525 62526
Frost dates near Decatur
- Elwin Apr 14 · Oct 24
- Forsyth Apr 14 · Oct 24
- Mt Zion Apr 16 · Oct 22
- Harristown Apr 14 · Oct 24
- Boody Apr 14 · Oct 24
- Oreana Apr 16 · Oct 22
- Macon Apr 14 · Oct 24
- Warrensburg Apr 14 · Oct 24
Frequently asked questions
When is the last frost in Decatur, IL?
The median last spring frost in Decatur, IL is April 14. There is still about a 10% chance of frost after May 1, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Decatur, IL?
The median first fall frost is October 24, with about a 10% chance of frost before October 11.
How long is the growing season in Decatur, IL?
About 193 days between the median last spring frost and first fall frost.
What planting zone is Decatur, IL?
Decatur, IL is in USDA hardiness zone 6a.