Modoc, IL frost dates
Last spring frostApr 8median date
First fall frostOct 30median date
Growing season205 daysfrost-free
Hardiness zone7aZone 7a
How Modoc compares
- In 8 years out of 10, the last spring frost in Modoc falls between March 22 and April 25, a 34-day window. The first fall frost falls between October 15 and November 13.
- The median last frost is 9 days earlier than the Illinois median of Apr 17.
- Its 205-day growing season is longer than 90% 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 7a median of Apr 16. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 7a chart.
- The weather station records an average of 99 nights a year at or below 32°F.
- Compared with Florissant, MO, 85 km away, the last frost here is 6 days later than there and the growing season is 11 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 22 |
| 50% (median) | April 8 |
| 10% (safe for tender plants) | April 25 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 15 |
| 50% (median) | October 30 |
| 90% (late) | November 13 |
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 Modoc, IL
Modoc, IL frost dates — last frost Apr 8, first frost Oct 30, zone 7a. whenisthelastfrost.com
Crop
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Start indoors: Jan 14 to Jan 28Transplant outside: Mar 11 to Mar 25
Start indoors: Jan 28 to Feb 11Transplant outside: Apr 22 to May 6
Start indoors: Jan 28 to Feb 11Transplant outside: Apr 22 to May 6
Start indoors: Feb 11 to Feb 25Transplant outside: Apr 15 to Apr 29
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 18 to Apr 1Sow outdoors: Mar 11 to Apr 15Plant for fall: Sep 4 to Oct 2
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 11 to Mar 25Sow outdoors: Mar 11 to Mar 25Plant for fall: Aug 21 to Sep 11
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 25 to Apr 8Plant for fall: Jul 24 to Aug 14
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 18 to Apr 1Plant for fall: Jul 24 to Aug 14
Start indoors: Feb 11 to Feb 25Transplant outside: Mar 25 to Apr 8Plant for fall: Jul 24 to Aug 14
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 29 to May 13Sow outdoors: Apr 29 to May 13
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 15 to Apr 29
Sow outdoors: Feb 25 to Mar 18Plant for fall: Aug 7 to Aug 28
Sow outdoors: Feb 25 to Mar 18Plant for fall: Sep 4 to Sep 25
Sow outdoors: Mar 4 to Apr 15Plant for fall: Sep 18 to Oct 9
Start indoors: Mar 11 to Mar 18Transplant outside: Apr 22 to Apr 29Sow outdoors: Apr 15 to Apr 29Plant for fall: Aug 14 to Aug 28
Start indoors: Mar 11 to Mar 18Sow outdoors: Apr 15 to Apr 29Plant for fall: Aug 21 to Sep 4
Start indoors: Mar 11 to Mar 18Sow outdoors: Apr 15 to Apr 29
Start indoors: Mar 11 to Mar 18Transplant outside: Apr 22 to May 6
Sow outdoors: Mar 18 to Apr 15Plant for fall: Aug 7 to Aug 21
Sow outdoors: Mar 18 to Apr 15Plant for fall: Aug 21 to Sep 4
Sow outdoors: Mar 18 to Apr 8
Sow outdoors: Mar 25 to Apr 22Plant for fall: Aug 21 to Sep 4
Sow outdoors: Mar 25 to Apr 15Plant for fall: Sep 4 to Sep 25
Sow outdoors: Apr 15 to May 6Plant for fall: Aug 14 to Aug 28
Sow outdoors: Apr 15 to Apr 29
Transplant outside: Apr 22 to May 13
Plant for fall: Oct 16 to Nov 20
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Modoc, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 14 – Jan 28 | Mar 11 – Mar 25 | — | — |
| Peppers | Jan 28 – Feb 11 | Apr 22 – May 6 | — | — |
| Eggplant | Jan 28 – Feb 11 | Apr 22 – May 6 | — | — |
| Tomatoes | Feb 11 – Feb 25 | Apr 15 – Apr 29 | — | — |
| Lettuce | Feb 11 – Feb 25 | Mar 18 – Apr 1 | Mar 11 – Apr 15 | Sep 4 – Oct 2 |
| Kale | Feb 11 – Feb 25 | Mar 11 – Mar 25 | Mar 11 – Mar 25 | Aug 21 – Sep 11 |
| Broccoli | Feb 11 – Feb 25 | Mar 25 – Apr 8 | — | Jul 24 – Aug 14 |
| Cabbage | Feb 11 – Feb 25 | Mar 18 – Apr 1 | — | Jul 24 – Aug 14 |
| Cauliflower | Feb 11 – Feb 25 | Mar 25 – Apr 8 | — | Jul 24 – Aug 14 |
| Okra | Feb 25 – Mar 11 | Apr 29 – May 13 | Apr 29 – May 13 | — |
| Basil | Feb 25 – Mar 11 | Apr 15 – Apr 29 | — | — |
| Peas | — | — | Feb 25 – Mar 18 | Aug 7 – Aug 28 |
| Spinach | — | — | Feb 25 – Mar 18 | Sep 4 – Sep 25 |
| Radishes | — | — | Mar 4 – Apr 15 | Sep 18 – Oct 9 |
| Cucumbers | Mar 11 – Mar 18 | Apr 22 – Apr 29 | Apr 15 – Apr 29 | Aug 14 – Aug 28 |
| Zucchini & Summer Squash | Mar 11 – Mar 18 | — | Apr 15 – Apr 29 | Aug 21 – Sep 4 |
| Winter Squash & Pumpkins | Mar 11 – Mar 18 | — | Apr 15 – Apr 29 | — |
| Melons & Watermelon | Mar 11 – Mar 18 | Apr 22 – May 6 | — | — |
| Carrots | — | — | Mar 18 – Apr 15 | Aug 7 – Aug 21 |
| Beets | — | — | Mar 18 – Apr 15 | Aug 21 – Sep 4 |
| Potatoes | — | — | Mar 18 – Apr 8 | — |
| Swiss Chard | — | — | Mar 25 – Apr 22 | Aug 21 – Sep 4 |
| Cilantro | — | — | Mar 25 – Apr 15 | Sep 4 – Sep 25 |
| Green Beans | — | — | Apr 15 – May 6 | Aug 14 – Aug 28 |
| Sweet Corn | — | — | Apr 15 – Apr 29 | — |
| Sweet Potatoes | — | Apr 22 – May 13 | — | — |
| Garlic | — | — | — | Oct 16 – Nov 20 |
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 Kaskaskia Rvr Navigation Lock, IL weather station, 10 km away (elevation 381 ft (116 m)).
Frost dates near Modoc
- Prairie Du Rocher Apr 8 · Oct 30
- Evansville Apr 8 · Oct 30
- Ellis Grove Apr 8 · Oct 30
- Renault Apr 9 · Oct 26
- Red Bud Apr 8 · Oct 30
- Walsh Apr 8 · Oct 30
- Baldwin Apr 12 · Oct 22
- Fults Apr 9 · Oct 26
- Menard Apr 8 · Oct 30
- Chester Apr 8 · Oct 30
Frequently asked questions
When is the last frost in Modoc, IL?
The median last spring frost in Modoc, IL is April 8. There is still about a 10% chance of frost after April 25, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Modoc, IL?
The median first fall frost is October 30, with about a 10% chance of frost before October 15.
How long is the growing season in Modoc, IL?
About 205 days between the median last spring frost and first fall frost.
What planting zone is Modoc, IL?
Modoc, IL is in USDA hardiness zone 7a.