Mount Vernon, IL frost dates
Last spring frostApr 11median date
First fall frostOct 22median date
Growing season194 daysfrost-free
Hardiness zone6bZone 6b
How Mount Vernon compares
- In 8 years out of 10, the last spring frost in Mount Vernon falls between March 30 and April 26, a 27-day window. The first fall frost falls between October 9 and November 1.
- The median last frost is 6 days earlier than the Illinois median of Apr 17.
- Its 194-day growing season is longer than 74% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 11 days earlier than the zone 6b median of Apr 22. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6b chart.
- The weather station records an average of 108 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 30 |
| 50% (median) | April 11 |
| 10% (safe for tender plants) | April 26 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 9 |
| 50% (median) | October 22 |
| 90% (late) | November 1 |
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 Mount Vernon, IL
Mount Vernon, IL frost dates — last frost Apr 11, first frost Oct 22, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Jan 17 to Jan 31Transplant outside: Mar 14 to Mar 28
Start indoors: Jan 31 to Feb 14Transplant outside: Apr 25 to May 9
Start indoors: Jan 31 to Feb 14Transplant outside: Apr 25 to May 9
Start indoors: Feb 14 to Feb 28Transplant outside: Apr 18 to May 2
Start indoors: Feb 14 to Feb 28Transplant outside: Mar 21 to Apr 4Sow outdoors: Mar 14 to Apr 18Plant for fall: Aug 27 to Sep 24
Start indoors: Feb 14 to Feb 28Transplant outside: Mar 14 to Mar 28Sow outdoors: Mar 14 to Mar 28Plant for fall: Aug 13 to Sep 3
Start indoors: Feb 14 to Feb 28Transplant outside: Mar 28 to Apr 11Plant for fall: Jul 16 to Aug 6
Start indoors: Feb 14 to Feb 28Transplant outside: Mar 21 to Apr 4Plant for fall: Jul 16 to Aug 6
Start indoors: Feb 14 to Feb 28Transplant outside: Mar 28 to Apr 11Plant for fall: Jul 16 to Aug 6
Start indoors: Feb 28 to Mar 14Transplant outside: May 2 to May 16Sow outdoors: May 2 to May 16
Start indoors: Feb 28 to Mar 14Transplant outside: Apr 18 to May 2
Sow outdoors: Feb 28 to Mar 21Plant for fall: Jul 30 to Aug 20
Sow outdoors: Feb 28 to Mar 21Plant for fall: Aug 27 to Sep 17
Sow outdoors: Mar 7 to Apr 18Plant for fall: Sep 10 to Oct 1
Start indoors: Mar 14 to Mar 21Transplant outside: Apr 25 to May 2Sow outdoors: Apr 18 to May 2Plant for fall: Aug 6 to Aug 20
Start indoors: Mar 14 to Mar 21Sow outdoors: Apr 18 to May 2Plant for fall: Aug 13 to Aug 27
Start indoors: Mar 14 to Mar 21Sow outdoors: Apr 18 to May 2
Start indoors: Mar 14 to Mar 21Transplant outside: Apr 25 to May 9
Sow outdoors: Mar 21 to Apr 18Plant for fall: Jul 30 to Aug 13
Sow outdoors: Mar 21 to Apr 18Plant for fall: Aug 13 to Aug 27
Sow outdoors: Mar 21 to Apr 11
Sow outdoors: Mar 28 to Apr 25Plant for fall: Aug 13 to Aug 27
Sow outdoors: Mar 28 to Apr 18Plant for fall: Aug 27 to Sep 17
Sow outdoors: Apr 18 to May 9Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 18 to May 2
Transplant outside: Apr 25 to May 16
Plant for fall: Oct 8 to Nov 12
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Mount Vernon, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 17 – Jan 31 | Mar 14 – Mar 28 | — | — |
| Peppers | Jan 31 – Feb 14 | Apr 25 – May 9 | — | — |
| Eggplant | Jan 31 – Feb 14 | Apr 25 – May 9 | — | — |
| Tomatoes | Feb 14 – Feb 28 | Apr 18 – May 2 | — | — |
| Lettuce | Feb 14 – Feb 28 | Mar 21 – Apr 4 | Mar 14 – Apr 18 | Aug 27 – Sep 24 |
| Kale | Feb 14 – Feb 28 | Mar 14 – Mar 28 | Mar 14 – Mar 28 | Aug 13 – Sep 3 |
| Broccoli | Feb 14 – Feb 28 | Mar 28 – Apr 11 | — | Jul 16 – Aug 6 |
| Cabbage | Feb 14 – Feb 28 | Mar 21 – Apr 4 | — | Jul 16 – Aug 6 |
| Cauliflower | Feb 14 – Feb 28 | Mar 28 – Apr 11 | — | Jul 16 – Aug 6 |
| Okra | Feb 28 – Mar 14 | May 2 – May 16 | May 2 – May 16 | — |
| Basil | Feb 28 – Mar 14 | Apr 18 – May 2 | — | — |
| Peas | — | — | Feb 28 – Mar 21 | Jul 30 – Aug 20 |
| Spinach | — | — | Feb 28 – Mar 21 | Aug 27 – Sep 17 |
| Radishes | — | — | Mar 7 – Apr 18 | Sep 10 – Oct 1 |
| Cucumbers | Mar 14 – Mar 21 | Apr 25 – May 2 | Apr 18 – May 2 | Aug 6 – Aug 20 |
| Zucchini & Summer Squash | Mar 14 – Mar 21 | — | Apr 18 – May 2 | Aug 13 – Aug 27 |
| Winter Squash & Pumpkins | Mar 14 – Mar 21 | — | Apr 18 – May 2 | — |
| Melons & Watermelon | Mar 14 – Mar 21 | Apr 25 – May 9 | — | — |
| Carrots | — | — | Mar 21 – Apr 18 | Jul 30 – Aug 13 |
| Beets | — | — | Mar 21 – Apr 18 | Aug 13 – Aug 27 |
| Potatoes | — | — | Mar 21 – Apr 11 | — |
| Swiss Chard | — | — | Mar 28 – Apr 25 | Aug 13 – Aug 27 |
| Cilantro | — | — | Mar 28 – Apr 18 | Aug 27 – Sep 17 |
| Green Beans | — | — | Apr 18 – May 9 | Aug 6 – Aug 20 |
| Sweet Corn | — | — | Apr 18 – May 2 | — |
| Sweet Potatoes | — | Apr 25 – May 16 | — | — |
| 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 Mt Vernon 3 Ne, IL weather station, 6 km away (elevation 489 ft (149 m)).
Frost dates near Mount Vernon
- Texico Apr 11 · Oct 22
- Opdyke Apr 11 · Oct 22
- Bonnie Apr 11 · Oct 22
- Bluford Apr 11 · Oct 22
- Dix Apr 9 · Oct 24
- Woodlawn Apr 9 · Oct 24
- Waltonville Apr 4 · Oct 27
- Belle Rive Apr 11 · Oct 22
- Nason Apr 4 · Oct 27
- Ina Apr 4 · Oct 28
Frequently asked questions
When is the last frost in Mount Vernon, IL?
The median last spring frost in Mount Vernon, IL is April 11. There is still about a 10% chance of frost after April 26, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Mount Vernon, IL?
The median first fall frost is October 22, with about a 10% chance of frost before October 9.
How long is the growing season in Mount Vernon, IL?
About 194 days between the median last spring frost and first fall frost.
What planting zone is Mount Vernon, IL?
Mount Vernon, IL is in USDA hardiness zone 6b.