Piasa, IL frost dates
Last spring frostApr 14median date
First fall frostOct 19median date
Growing season188 daysfrost-free
Hardiness zone6bZone 6b
How Piasa compares
- In 8 years out of 10, the last spring frost in Piasa falls between March 31 and April 30, a 30-day window. The first fall frost falls between October 7 and November 1.
- The median last frost is 3 days earlier than the Illinois median of Apr 17.
- Its 188-day growing season is longer than 51% 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 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 118 nights a year at or below 32°F.
- Compared with Florissant, MO, 43 km away, the last frost here is 12 days later than there and the growing season is 28 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 31 |
| 50% (median) | April 14 |
| 10% (safe for tender plants) | April 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 7 |
| 50% (median) | October 19 |
| 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 Piasa, IL
Piasa, IL frost dates — last frost Apr 14, first frost Oct 19, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Jan 20 to Feb 3Transplant outside: Mar 17 to Mar 31
Start indoors: Feb 3 to Feb 17Transplant outside: Apr 28 to May 12
Start indoors: Feb 3 to Feb 17Transplant outside: Apr 28 to May 12
Start indoors: Feb 17 to Mar 3Transplant outside: Apr 21 to May 5
Start indoors: Feb 17 to Mar 3Transplant outside: Mar 24 to Apr 7Sow outdoors: Mar 17 to Apr 21Plant for fall: Aug 24 to Sep 21
Start indoors: Feb 17 to Mar 3Transplant outside: Mar 17 to Mar 31Sow outdoors: Mar 17 to Mar 31Plant for fall: Aug 10 to Aug 31
Start indoors: Feb 17 to Mar 3Transplant outside: Mar 31 to Apr 14Plant for fall: Jul 13 to Aug 3
Start indoors: Feb 17 to Mar 3Transplant outside: Mar 24 to Apr 7Plant for fall: Jul 13 to Aug 3
Start indoors: Feb 17 to Mar 3Transplant outside: Mar 31 to Apr 14Plant for fall: Jul 13 to Aug 3
Start indoors: Mar 3 to Mar 17Transplant outside: May 5 to May 19Sow outdoors: May 5 to May 19
Start indoors: Mar 3 to Mar 17Transplant outside: Apr 21 to May 5
Sow outdoors: Mar 3 to Mar 24Plant for fall: Jul 27 to Aug 17
Sow outdoors: Mar 3 to Mar 24Plant for fall: Aug 24 to Sep 14
Sow outdoors: Mar 10 to Apr 21Plant for fall: Sep 7 to Sep 28
Start indoors: Mar 17 to Mar 24Transplant outside: Apr 28 to May 5Sow outdoors: Apr 21 to May 5Plant for fall: Aug 3 to Aug 17
Start indoors: Mar 17 to Mar 24Sow outdoors: Apr 21 to May 5Plant for fall: Aug 10 to Aug 24
Start indoors: Mar 17 to Mar 24Sow outdoors: Apr 21 to May 5
Start indoors: Mar 17 to Mar 24Transplant outside: Apr 28 to May 12
Sow outdoors: Mar 24 to Apr 21Plant for fall: Jul 27 to Aug 10
Sow outdoors: Mar 24 to Apr 21Plant for fall: Aug 10 to Aug 24
Sow outdoors: Mar 24 to Apr 14
Sow outdoors: Mar 31 to Apr 28Plant for fall: Aug 10 to Aug 24
Sow outdoors: Mar 31 to Apr 21Plant for fall: Aug 24 to Sep 14
Sow outdoors: Apr 21 to May 12Plant for fall: Aug 3 to Aug 17
Sow outdoors: Apr 21 to May 5
Transplant outside: Apr 28 to May 19
Plant for fall: Oct 5 to Nov 9
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Piasa, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 20 – Feb 3 | Mar 17 – Mar 31 | — | — |
| Peppers | Feb 3 – Feb 17 | Apr 28 – May 12 | — | — |
| Eggplant | Feb 3 – Feb 17 | Apr 28 – May 12 | — | — |
| Tomatoes | Feb 17 – Mar 3 | Apr 21 – May 5 | — | — |
| Lettuce | Feb 17 – Mar 3 | Mar 24 – Apr 7 | Mar 17 – Apr 21 | Aug 24 – Sep 21 |
| Kale | Feb 17 – Mar 3 | Mar 17 – Mar 31 | Mar 17 – Mar 31 | Aug 10 – Aug 31 |
| Broccoli | Feb 17 – Mar 3 | Mar 31 – Apr 14 | — | Jul 13 – Aug 3 |
| Cabbage | Feb 17 – Mar 3 | Mar 24 – Apr 7 | — | Jul 13 – Aug 3 |
| Cauliflower | Feb 17 – Mar 3 | Mar 31 – Apr 14 | — | Jul 13 – Aug 3 |
| Okra | Mar 3 – Mar 17 | May 5 – May 19 | May 5 – May 19 | — |
| Basil | Mar 3 – Mar 17 | Apr 21 – May 5 | — | — |
| Peas | — | — | Mar 3 – Mar 24 | Jul 27 – Aug 17 |
| Spinach | — | — | Mar 3 – Mar 24 | Aug 24 – Sep 14 |
| Radishes | — | — | Mar 10 – Apr 21 | Sep 7 – Sep 28 |
| Cucumbers | Mar 17 – Mar 24 | Apr 28 – May 5 | Apr 21 – May 5 | Aug 3 – Aug 17 |
| Zucchini & Summer Squash | Mar 17 – Mar 24 | — | Apr 21 – May 5 | Aug 10 – Aug 24 |
| Winter Squash & Pumpkins | Mar 17 – Mar 24 | — | Apr 21 – May 5 | — |
| Melons & Watermelon | Mar 17 – Mar 24 | Apr 28 – May 12 | — | — |
| Carrots | — | — | Mar 24 – Apr 21 | Jul 27 – Aug 10 |
| Beets | — | — | Mar 24 – Apr 21 | Aug 10 – Aug 24 |
| Potatoes | — | — | Mar 24 – Apr 14 | — |
| Swiss Chard | — | — | Mar 31 – Apr 28 | Aug 10 – Aug 24 |
| Cilantro | — | — | Mar 31 – Apr 21 | Aug 24 – Sep 14 |
| Green Beans | — | — | Apr 21 – May 12 | Aug 3 – Aug 17 |
| Sweet Corn | — | — | Apr 21 – May 5 | — |
| Sweet Potatoes | — | Apr 28 – May 19 | — | — |
| Garlic | — | — | — | Oct 5 – Nov 9 |
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 Jerseyville 2 Sw, IL weather station, 19 km away (elevation 630 ft (192 m)).
Frost dates near Piasa
- Fidelity Apr 14 · Oct 19
- Brighton Apr 14 · Oct 19
- Medora Apr 14 · Oct 19
- Bunker Hill Apr 4 · Nov 5
- Shipman Apr 14 · Oct 21
- Chesterfield Apr 14 · Oct 21
- Dow Apr 14 · Oct 19
- Jerseyville Apr 14 · Oct 19
- Dorsey Apr 4 · Nov 5
- Godfrey Apr 4 · Nov 5
Frequently asked questions
When is the last frost in Piasa, IL?
The median last spring frost in Piasa, IL is April 14. There is still about a 10% chance of frost after April 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Piasa, IL?
The median first fall frost is October 19, with about a 10% chance of frost before October 7.
How long is the growing season in Piasa, IL?
About 188 days between the median last spring frost and first fall frost.
What planting zone is Piasa, IL?
Piasa, IL is in USDA hardiness zone 6b.