Morton, IL frost dates
Last spring frostApr 21median date
First fall frostOct 17median date
Growing season179 daysfrost-free
Hardiness zone6aZone 6a
How Morton compares
- In 8 years out of 10, the last spring frost in Morton falls between April 7 and May 7, a 30-day window. The first fall frost falls between October 3 and October 30.
- The median last frost is 4 days later than the Illinois median of Apr 17.
- Its 179-day growing season is longer than 26% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 8 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 134 nights a year at or below 32°F.
- Compared with Peoria, IL, 20 km away, the last frost here is 5 days later than there and the growing season is 11 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 7 |
| 50% (median) | April 21 |
| 10% (safe for tender plants) | May 7 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 3 |
| 50% (median) | October 17 |
| 90% (late) | October 30 |
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 Morton, IL
Morton, IL frost dates — last frost Apr 21, first frost Oct 17, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Jan 27 to Feb 10Transplant outside: Mar 24 to Apr 7
Start indoors: Feb 10 to Feb 24Transplant outside: May 5 to May 19
Start indoors: Feb 10 to Feb 24Transplant outside: May 5 to May 19
Start indoors: Feb 24 to Mar 10Transplant outside: Apr 28 to May 12
Start indoors: Feb 24 to Mar 10Transplant outside: Mar 31 to Apr 14Sow outdoors: Mar 24 to Apr 28Plant for fall: Aug 22 to Sep 19
Start indoors: Feb 24 to Mar 10Transplant outside: Mar 24 to Apr 7Sow outdoors: Mar 24 to Apr 7Plant for fall: Aug 8 to Aug 29
Start indoors: Feb 24 to Mar 10Transplant outside: Apr 7 to Apr 21Plant for fall: Jul 11 to Aug 1
Start indoors: Feb 24 to Mar 10Transplant outside: Mar 31 to Apr 14Plant for fall: Jul 11 to Aug 1
Start indoors: Feb 24 to Mar 10Transplant outside: Apr 7 to Apr 21Plant for fall: Jul 11 to Aug 1
Start indoors: Mar 10 to Mar 24Transplant outside: May 12 to May 26Sow outdoors: May 12 to May 26
Start indoors: Mar 10 to Mar 24Transplant outside: Apr 28 to May 12
Sow outdoors: Mar 10 to Mar 31Plant for fall: Jul 25 to Aug 15
Sow outdoors: Mar 10 to Mar 31Plant for fall: Aug 22 to Sep 12
Sow outdoors: Mar 17 to Apr 28Plant for fall: Sep 5 to Sep 26
Start indoors: Mar 24 to Mar 31Transplant outside: May 5 to May 12Sow outdoors: Apr 28 to May 12Plant for fall: Aug 1 to Aug 15
Start indoors: Mar 24 to Mar 31Sow outdoors: Apr 28 to May 12Plant for fall: Aug 8 to Aug 22
Start indoors: Mar 24 to Mar 31Sow outdoors: Apr 28 to May 12
Start indoors: Mar 24 to Mar 31Transplant outside: May 5 to May 19
Sow outdoors: Mar 31 to Apr 28Plant for fall: Jul 25 to Aug 8
Sow outdoors: Mar 31 to Apr 28Plant for fall: Aug 8 to Aug 22
Sow outdoors: Mar 31 to Apr 21
Sow outdoors: Apr 7 to May 5Plant for fall: Aug 8 to Aug 22
Sow outdoors: Apr 7 to Apr 28Plant for fall: Aug 22 to Sep 12
Sow outdoors: Apr 28 to May 19Plant for fall: Aug 1 to Aug 15
Sow outdoors: Apr 28 to May 12
Transplant outside: May 5 to May 26
Plant for fall: Oct 3 to Nov 7
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Morton, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 27 – Feb 10 | Mar 24 – Apr 7 | — | — |
| Peppers | Feb 10 – Feb 24 | May 5 – May 19 | — | — |
| Eggplant | Feb 10 – Feb 24 | May 5 – May 19 | — | — |
| Tomatoes | Feb 24 – Mar 10 | Apr 28 – May 12 | — | — |
| Lettuce | Feb 24 – Mar 10 | Mar 31 – Apr 14 | Mar 24 – Apr 28 | Aug 22 – Sep 19 |
| Kale | Feb 24 – Mar 10 | Mar 24 – Apr 7 | Mar 24 – Apr 7 | Aug 8 – Aug 29 |
| Broccoli | Feb 24 – Mar 10 | Apr 7 – Apr 21 | — | Jul 11 – Aug 1 |
| Cabbage | Feb 24 – Mar 10 | Mar 31 – Apr 14 | — | Jul 11 – Aug 1 |
| Cauliflower | Feb 24 – Mar 10 | Apr 7 – Apr 21 | — | Jul 11 – Aug 1 |
| Okra | Mar 10 – Mar 24 | May 12 – May 26 | May 12 – May 26 | — |
| Basil | Mar 10 – Mar 24 | Apr 28 – May 12 | — | — |
| Peas | — | — | Mar 10 – Mar 31 | Jul 25 – Aug 15 |
| Spinach | — | — | Mar 10 – Mar 31 | Aug 22 – Sep 12 |
| Radishes | — | — | Mar 17 – Apr 28 | Sep 5 – Sep 26 |
| Cucumbers | Mar 24 – Mar 31 | May 5 – May 12 | Apr 28 – May 12 | Aug 1 – Aug 15 |
| Zucchini & Summer Squash | Mar 24 – Mar 31 | — | Apr 28 – May 12 | Aug 8 – Aug 22 |
| Winter Squash & Pumpkins | Mar 24 – Mar 31 | — | Apr 28 – May 12 | — |
| Melons & Watermelon | Mar 24 – Mar 31 | May 5 – May 19 | — | — |
| Carrots | — | — | Mar 31 – Apr 28 | Jul 25 – Aug 8 |
| Beets | — | — | Mar 31 – Apr 28 | Aug 8 – Aug 22 |
| Potatoes | — | — | Mar 31 – Apr 21 | — |
| Swiss Chard | — | — | Apr 7 – May 5 | Aug 8 – Aug 22 |
| Cilantro | — | — | Apr 7 – Apr 28 | Aug 22 – Sep 12 |
| Green Beans | — | — | Apr 28 – May 19 | Aug 1 – Aug 15 |
| Sweet Corn | — | — | Apr 28 – May 12 | — |
| Sweet Potatoes | — | May 5 – May 26 | — | — |
| Garlic | — | — | — | Oct 3 – Nov 7 |
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 Congerville 2nw, IL weather station, 18 km away (elevation 640 ft (195 m)).
Frost dates near Morton
- Groveland Apr 16 · Oct 23
- Washington Apr 21 · Oct 17
- East Peoria Apr 16 · Oct 23
- Deer Creek Apr 21 · Oct 17
- Creve Coeur Apr 16 · Oct 23
- Tremont Apr 21 · Oct 17
- Mackinaw Apr 21 · Oct 17
- Goodfield Apr 21 · Oct 17
- Pekin Apr 16 · Oct 23
- Peoria Heights Apr 16 · Oct 23
Frequently asked questions
When is the last frost in Morton, IL?
The median last spring frost in Morton, IL is April 21. There is still about a 10% chance of frost after May 7, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Morton, IL?
The median first fall frost is October 17, with about a 10% chance of frost before October 3.
How long is the growing season in Morton, IL?
About 179 days between the median last spring frost and first fall frost.
What planting zone is Morton, IL?
Morton, IL is in USDA hardiness zone 6a.