Unity, IL frost dates
Last spring frostApr 2median date
First fall frostOct 31median date
Growing season212 daysfrost-free
Hardiness zone7aZone 7a
How Unity compares
- In 8 years out of 10, the last spring frost in Unity falls between March 19 and April 17, a 29-day window. The first fall frost falls between October 18 and November 13.
- The median last frost is 15 days earlier than the Illinois median of Apr 17.
- Its 212-day growing season is longer than 97% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 14 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 81 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 19 |
| 50% (median) | April 2 |
| 10% (safe for tender plants) | April 17 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 18 |
| 50% (median) | October 31 |
| 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 Unity, IL
Unity, IL frost dates — last frost Apr 2, first frost Oct 31, zone 7a. whenisthelastfrost.com
Crop
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Start indoors: Jan 8 to Jan 22Transplant outside: Mar 5 to Mar 19
Start indoors: Jan 22 to Feb 5Transplant outside: Apr 16 to Apr 30
Start indoors: Jan 22 to Feb 5Transplant outside: Apr 16 to Apr 30
Start indoors: Feb 5 to Feb 19Transplant outside: Apr 9 to Apr 23
Start indoors: Feb 5 to Feb 19Transplant outside: Mar 12 to Mar 26Sow outdoors: Mar 5 to Apr 9Plant for fall: Sep 5 to Oct 3
Start indoors: Feb 5 to Feb 19Transplant outside: Mar 5 to Mar 19Sow outdoors: Mar 5 to Mar 19Plant for fall: Aug 22 to Sep 12
Start indoors: Feb 5 to Feb 19Transplant outside: Mar 19 to Apr 2Plant for fall: Jul 25 to Aug 15
Start indoors: Feb 5 to Feb 19Transplant outside: Mar 12 to Mar 26Plant for fall: Jul 25 to Aug 15
Start indoors: Feb 5 to Feb 19Transplant outside: Mar 19 to Apr 2Plant for fall: Jul 25 to Aug 15
Start indoors: Feb 19 to Mar 5Transplant outside: Apr 23 to May 7Sow outdoors: Apr 23 to May 7
Start indoors: Feb 19 to Mar 5Transplant outside: Apr 9 to Apr 23
Sow outdoors: Feb 19 to Mar 12Plant for fall: Aug 8 to Aug 29
Sow outdoors: Feb 19 to Mar 12Plant for fall: Sep 5 to Sep 26
Sow outdoors: Feb 26 to Apr 9Plant for fall: Sep 19 to Oct 10
Start indoors: Mar 5 to Mar 12Transplant outside: Apr 16 to Apr 23Sow outdoors: Apr 9 to Apr 23Plant for fall: Aug 15 to Aug 29
Start indoors: Mar 5 to Mar 12Sow outdoors: Apr 9 to Apr 23Plant for fall: Aug 22 to Sep 5
Start indoors: Mar 5 to Mar 12Sow outdoors: Apr 9 to Apr 23
Start indoors: Mar 5 to Mar 12Transplant outside: Apr 16 to Apr 30
Sow outdoors: Mar 12 to Apr 9Plant for fall: Aug 8 to Aug 22
Sow outdoors: Mar 12 to Apr 9Plant for fall: Aug 22 to Sep 5
Sow outdoors: Mar 12 to Apr 2
Sow outdoors: Mar 19 to Apr 16Plant for fall: Aug 22 to Sep 5
Sow outdoors: Mar 19 to Apr 9Plant for fall: Sep 5 to Sep 26
Sow outdoors: Apr 9 to Apr 30Plant for fall: Aug 15 to Aug 29
Sow outdoors: Apr 9 to Apr 23
Transplant outside: Apr 16 to May 7
Plant for fall: Oct 17 to Nov 21
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Unity, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 8 – Jan 22 | Mar 5 – Mar 19 | — | — |
| Peppers | Jan 22 – Feb 5 | Apr 16 – Apr 30 | — | — |
| Eggplant | Jan 22 – Feb 5 | Apr 16 – Apr 30 | — | — |
| Tomatoes | Feb 5 – Feb 19 | Apr 9 – Apr 23 | — | — |
| Lettuce | Feb 5 – Feb 19 | Mar 12 – Mar 26 | Mar 5 – Apr 9 | Sep 5 – Oct 3 |
| Kale | Feb 5 – Feb 19 | Mar 5 – Mar 19 | Mar 5 – Mar 19 | Aug 22 – Sep 12 |
| Broccoli | Feb 5 – Feb 19 | Mar 19 – Apr 2 | — | Jul 25 – Aug 15 |
| Cabbage | Feb 5 – Feb 19 | Mar 12 – Mar 26 | — | Jul 25 – Aug 15 |
| Cauliflower | Feb 5 – Feb 19 | Mar 19 – Apr 2 | — | Jul 25 – Aug 15 |
| Okra | Feb 19 – Mar 5 | Apr 23 – May 7 | Apr 23 – May 7 | — |
| Basil | Feb 19 – Mar 5 | Apr 9 – Apr 23 | — | — |
| Peas | — | — | Feb 19 – Mar 12 | Aug 8 – Aug 29 |
| Spinach | — | — | Feb 19 – Mar 12 | Sep 5 – Sep 26 |
| Radishes | — | — | Feb 26 – Apr 9 | Sep 19 – Oct 10 |
| Cucumbers | Mar 5 – Mar 12 | Apr 16 – Apr 23 | Apr 9 – Apr 23 | Aug 15 – Aug 29 |
| Zucchini & Summer Squash | Mar 5 – Mar 12 | — | Apr 9 – Apr 23 | Aug 22 – Sep 5 |
| Winter Squash & Pumpkins | Mar 5 – Mar 12 | — | Apr 9 – Apr 23 | — |
| Melons & Watermelon | Mar 5 – Mar 12 | Apr 16 – Apr 30 | — | — |
| Carrots | — | — | Mar 12 – Apr 9 | Aug 8 – Aug 22 |
| Beets | — | — | Mar 12 – Apr 9 | Aug 22 – Sep 5 |
| Potatoes | — | — | Mar 12 – Apr 2 | — |
| Swiss Chard | — | — | Mar 19 – Apr 16 | Aug 22 – Sep 5 |
| Cilantro | — | — | Mar 19 – Apr 9 | Sep 5 – Sep 26 |
| Green Beans | — | — | Apr 9 – Apr 30 | Aug 15 – Aug 29 |
| Sweet Corn | — | — | Apr 9 – Apr 23 | — |
| Sweet Potatoes | — | Apr 16 – May 7 | — | — |
| Garlic | — | — | — | Oct 17 – Nov 21 |
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 Cairo 3n, IL weather station, 18 km away (elevation 312 ft (95 m)).
Frost dates near Unity
- Olive Branch Apr 5 · Oct 25
- Miller City Apr 2 · Oct 31
- Tamms Apr 3 · Nov 5
- Mounds Apr 2 · Oct 31
- Villa Ridge Apr 2 · Oct 31
- Pulaski Apr 3 · Nov 5
- Thebes Apr 5 · Oct 25
- Mound City Apr 2 · Oct 31
- Ullin Apr 3 · Nov 5
- Mc Clure Apr 5 · Oct 25
Frequently asked questions
When is the last frost in Unity, IL?
The median last spring frost in Unity, IL is April 2. There is still about a 10% chance of frost after April 17, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Unity, IL?
The median first fall frost is October 31, with about a 10% chance of frost before October 18.
How long is the growing season in Unity, IL?
About 212 days between the median last spring frost and first fall frost.
What planting zone is Unity, IL?
Unity, IL is in USDA hardiness zone 7a.