Herrin, IL frost dates
Last spring frostApr 9median date
First fall frostOct 22median date
Growing season196 daysfrost-free
Hardiness zone7aZone 7a
How Herrin compares
- In 8 years out of 10, the last spring frost in Herrin falls between March 25 and April 25, a 31-day window. The first fall frost falls between October 10 and November 2.
- The median last frost is 8 days earlier than the Illinois median of Apr 17.
- Its 196-day growing season is longer than 78% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 7 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 103 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 25 |
| 50% (median) | April 9 |
| 10% (safe for tender plants) | April 25 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 10 |
| 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 Herrin, IL
Herrin, IL frost dates — last frost Apr 9, first frost Oct 22, zone 7a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Jan 15 to Jan 29Transplant outside: Mar 12 to Mar 26
Start indoors: Jan 29 to Feb 12Transplant outside: Apr 23 to May 7
Start indoors: Jan 29 to Feb 12Transplant outside: Apr 23 to May 7
Start indoors: Feb 12 to Feb 26Transplant outside: Apr 16 to Apr 30
Start indoors: Feb 12 to Feb 26Transplant outside: Mar 19 to Apr 2Sow outdoors: Mar 12 to Apr 16Plant for fall: Aug 27 to Sep 24
Start indoors: Feb 12 to Feb 26Transplant outside: Mar 12 to Mar 26Sow outdoors: Mar 12 to Mar 26Plant for fall: Aug 13 to Sep 3
Start indoors: Feb 12 to Feb 26Transplant outside: Mar 26 to Apr 9Plant for fall: Jul 16 to Aug 6
Start indoors: Feb 12 to Feb 26Transplant outside: Mar 19 to Apr 2Plant for fall: Jul 16 to Aug 6
Start indoors: Feb 12 to Feb 26Transplant outside: Mar 26 to Apr 9Plant for fall: Jul 16 to Aug 6
Start indoors: Feb 26 to Mar 12Transplant outside: Apr 30 to May 14Sow outdoors: Apr 30 to May 14
Start indoors: Feb 26 to Mar 12Transplant outside: Apr 16 to Apr 30
Sow outdoors: Feb 26 to Mar 19Plant for fall: Jul 30 to Aug 20
Sow outdoors: Feb 26 to Mar 19Plant for fall: Aug 27 to Sep 17
Sow outdoors: Mar 5 to Apr 16Plant for fall: Sep 10 to Oct 1
Start indoors: Mar 12 to Mar 19Transplant outside: Apr 23 to Apr 30Sow outdoors: Apr 16 to Apr 30Plant for fall: Aug 6 to Aug 20
Start indoors: Mar 12 to Mar 19Sow outdoors: Apr 16 to Apr 30Plant for fall: Aug 13 to Aug 27
Start indoors: Mar 12 to Mar 19Sow outdoors: Apr 16 to Apr 30
Start indoors: Mar 12 to Mar 19Transplant outside: Apr 23 to May 7
Sow outdoors: Mar 19 to Apr 16Plant for fall: Jul 30 to Aug 13
Sow outdoors: Mar 19 to Apr 16Plant for fall: Aug 13 to Aug 27
Sow outdoors: Mar 19 to Apr 9
Sow outdoors: Mar 26 to Apr 23Plant for fall: Aug 13 to Aug 27
Sow outdoors: Mar 26 to Apr 16Plant for fall: Aug 27 to Sep 17
Sow outdoors: Apr 16 to May 7Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 16 to Apr 30
Transplant outside: Apr 23 to May 14
Plant for fall: Oct 8 to Nov 12
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Herrin, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 15 – Jan 29 | Mar 12 – Mar 26 | — | — |
| Peppers | Jan 29 – Feb 12 | Apr 23 – May 7 | — | — |
| Eggplant | Jan 29 – Feb 12 | Apr 23 – May 7 | — | — |
| Tomatoes | Feb 12 – Feb 26 | Apr 16 – Apr 30 | — | — |
| Lettuce | Feb 12 – Feb 26 | Mar 19 – Apr 2 | Mar 12 – Apr 16 | Aug 27 – Sep 24 |
| Kale | Feb 12 – Feb 26 | Mar 12 – Mar 26 | Mar 12 – Mar 26 | Aug 13 – Sep 3 |
| Broccoli | Feb 12 – Feb 26 | Mar 26 – Apr 9 | — | Jul 16 – Aug 6 |
| Cabbage | Feb 12 – Feb 26 | Mar 19 – Apr 2 | — | Jul 16 – Aug 6 |
| Cauliflower | Feb 12 – Feb 26 | Mar 26 – Apr 9 | — | Jul 16 – Aug 6 |
| Okra | Feb 26 – Mar 12 | Apr 30 – May 14 | Apr 30 – May 14 | — |
| Basil | Feb 26 – Mar 12 | Apr 16 – Apr 30 | — | — |
| Peas | — | — | Feb 26 – Mar 19 | Jul 30 – Aug 20 |
| Spinach | — | — | Feb 26 – Mar 19 | Aug 27 – Sep 17 |
| Radishes | — | — | Mar 5 – Apr 16 | Sep 10 – Oct 1 |
| Cucumbers | Mar 12 – Mar 19 | Apr 23 – Apr 30 | Apr 16 – Apr 30 | Aug 6 – Aug 20 |
| Zucchini & Summer Squash | Mar 12 – Mar 19 | — | Apr 16 – Apr 30 | Aug 13 – Aug 27 |
| Winter Squash & Pumpkins | Mar 12 – Mar 19 | — | Apr 16 – Apr 30 | — |
| Melons & Watermelon | Mar 12 – Mar 19 | Apr 23 – May 7 | — | — |
| Carrots | — | — | Mar 19 – Apr 16 | Jul 30 – Aug 13 |
| Beets | — | — | Mar 19 – Apr 16 | Aug 13 – Aug 27 |
| Potatoes | — | — | Mar 19 – Apr 9 | — |
| Swiss Chard | — | — | Mar 26 – Apr 23 | Aug 13 – Aug 27 |
| Cilantro | — | — | Mar 26 – Apr 16 | Aug 27 – Sep 17 |
| Green Beans | — | — | Apr 16 – May 7 | Aug 6 – Aug 20 |
| Sweet Corn | — | — | Apr 16 – Apr 30 | — |
| Sweet Potatoes | — | Apr 23 – May 14 | — | — |
| 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 Carbondale Sewage Plt, IL weather station, 15 km away (elevation 390 ft (119 m)).
Frost dates near Herrin
- Energy Apr 9 · Oct 22
- Colp Apr 9 · Oct 22
- Freeman Spur Apr 4 · Oct 27
- Carterville Apr 9 · Oct 22
- Cambria Apr 9 · Oct 22
- Johnston City Apr 4 · Oct 28
- Zeigler Apr 6 · Oct 22
- Hurst Apr 9 · Oct 22
- Royalton Apr 6 · Oct 22
- Marion Apr 9 · Oct 22
Frequently asked questions
When is the last frost in Herrin, IL?
The median last spring frost in Herrin, IL is April 9. 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 Herrin, IL?
The median first fall frost is October 22, with about a 10% chance of frost before October 10.
How long is the growing season in Herrin, IL?
About 196 days between the median last spring frost and first fall frost.
What planting zone is Herrin, IL?
Herrin, IL is in USDA hardiness zone 7a.