Royalton, IL frost dates
Last spring frostApr 6median date
First fall frostOct 22median date
Growing season199 daysfrost-free
Hardiness zone7aZone 7a
How Royalton compares
- In 8 years out of 10, the last spring frost in Royalton falls between March 23 and April 22, a 30-day window. The first fall frost falls between October 9 and November 5.
- The median last frost is 11 days earlier than the Illinois median of Apr 17.
- Its 199-day growing season is longer than 82% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 10 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 93 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 23 |
| 50% (median) | April 6 |
| 10% (safe for tender plants) | April 22 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 9 |
| 50% (median) | October 22 |
| 90% (late) | November 5 |
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 Royalton, IL
Royalton, IL frost dates — last frost Apr 6, first frost Oct 22, zone 7a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Jan 12 to Jan 26Transplant outside: Mar 9 to Mar 23
Start indoors: Jan 26 to Feb 9Transplant outside: Apr 20 to May 4
Start indoors: Jan 26 to Feb 9Transplant outside: Apr 20 to May 4
Start indoors: Feb 9 to Feb 23Transplant outside: Apr 13 to Apr 27
Start indoors: Feb 9 to Feb 23Transplant outside: Mar 16 to Mar 30Sow outdoors: Mar 9 to Apr 13Plant for fall: Aug 27 to Sep 24
Start indoors: Feb 9 to Feb 23Transplant outside: Mar 9 to Mar 23Sow outdoors: Mar 9 to Mar 23Plant for fall: Aug 13 to Sep 3
Start indoors: Feb 9 to Feb 23Transplant outside: Mar 23 to Apr 6Plant for fall: Jul 16 to Aug 6
Start indoors: Feb 9 to Feb 23Transplant outside: Mar 16 to Mar 30Plant for fall: Jul 16 to Aug 6
Start indoors: Feb 9 to Feb 23Transplant outside: Mar 23 to Apr 6Plant for fall: Jul 16 to Aug 6
Start indoors: Feb 23 to Mar 9Transplant outside: Apr 27 to May 11Sow outdoors: Apr 27 to May 11
Start indoors: Feb 23 to Mar 9Transplant outside: Apr 13 to Apr 27
Sow outdoors: Feb 23 to Mar 16Plant for fall: Jul 30 to Aug 20
Sow outdoors: Feb 23 to Mar 16Plant for fall: Aug 27 to Sep 17
Sow outdoors: Mar 2 to Apr 13Plant for fall: Sep 10 to Oct 1
Start indoors: Mar 9 to Mar 16Transplant outside: Apr 20 to Apr 27Sow outdoors: Apr 13 to Apr 27Plant for fall: Aug 6 to Aug 20
Start indoors: Mar 9 to Mar 16Sow outdoors: Apr 13 to Apr 27Plant for fall: Aug 13 to Aug 27
Start indoors: Mar 9 to Mar 16Sow outdoors: Apr 13 to Apr 27
Start indoors: Mar 9 to Mar 16Transplant outside: Apr 20 to May 4
Sow outdoors: Mar 16 to Apr 13Plant for fall: Jul 30 to Aug 13
Sow outdoors: Mar 16 to Apr 13Plant for fall: Aug 13 to Aug 27
Sow outdoors: Mar 16 to Apr 6
Sow outdoors: Mar 23 to Apr 20Plant for fall: Aug 13 to Aug 27
Sow outdoors: Mar 23 to Apr 13Plant for fall: Aug 27 to Sep 17
Sow outdoors: Apr 13 to May 4Plant for fall: Aug 6 to Aug 20
Sow outdoors: Apr 13 to Apr 27
Transplant outside: Apr 20 to May 11
Plant for fall: Oct 8 to Nov 12
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Royalton, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 12 – Jan 26 | Mar 9 – Mar 23 | — | — |
| Peppers | Jan 26 – Feb 9 | Apr 20 – May 4 | — | — |
| Eggplant | Jan 26 – Feb 9 | Apr 20 – May 4 | — | — |
| Tomatoes | Feb 9 – Feb 23 | Apr 13 – Apr 27 | — | — |
| Lettuce | Feb 9 – Feb 23 | Mar 16 – Mar 30 | Mar 9 – Apr 13 | Aug 27 – Sep 24 |
| Kale | Feb 9 – Feb 23 | Mar 9 – Mar 23 | Mar 9 – Mar 23 | Aug 13 – Sep 3 |
| Broccoli | Feb 9 – Feb 23 | Mar 23 – Apr 6 | — | Jul 16 – Aug 6 |
| Cabbage | Feb 9 – Feb 23 | Mar 16 – Mar 30 | — | Jul 16 – Aug 6 |
| Cauliflower | Feb 9 – Feb 23 | Mar 23 – Apr 6 | — | Jul 16 – Aug 6 |
| Okra | Feb 23 – Mar 9 | Apr 27 – May 11 | Apr 27 – May 11 | — |
| Basil | Feb 23 – Mar 9 | Apr 13 – Apr 27 | — | — |
| Peas | — | — | Feb 23 – Mar 16 | Jul 30 – Aug 20 |
| Spinach | — | — | Feb 23 – Mar 16 | Aug 27 – Sep 17 |
| Radishes | — | — | Mar 2 – Apr 13 | Sep 10 – Oct 1 |
| Cucumbers | Mar 9 – Mar 16 | Apr 20 – Apr 27 | Apr 13 – Apr 27 | Aug 6 – Aug 20 |
| Zucchini & Summer Squash | Mar 9 – Mar 16 | — | Apr 13 – Apr 27 | Aug 13 – Aug 27 |
| Winter Squash & Pumpkins | Mar 9 – Mar 16 | — | Apr 13 – Apr 27 | — |
| Melons & Watermelon | Mar 9 – Mar 16 | Apr 20 – May 4 | — | — |
| Carrots | — | — | Mar 16 – Apr 13 | Jul 30 – Aug 13 |
| Beets | — | — | Mar 16 – Apr 13 | Aug 13 – Aug 27 |
| Potatoes | — | — | Mar 16 – Apr 6 | — |
| Swiss Chard | — | — | Mar 23 – Apr 20 | Aug 13 – Aug 27 |
| Cilantro | — | — | Mar 23 – Apr 13 | Aug 27 – Sep 17 |
| Green Beans | — | — | Apr 13 – May 4 | Aug 6 – Aug 20 |
| Sweet Corn | — | — | Apr 13 – Apr 27 | — |
| Sweet Potatoes | — | Apr 20 – May 11 | — | — |
| 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 Du Quoin 4 Se, IL weather station, 14 km away (elevation 420 ft (128 m)).
Frost dates near Royalton
- Hurst Apr 9 · Oct 22
- Zeigler Apr 6 · Oct 22
- Colp Apr 9 · Oct 22
- Mulkeytown Apr 6 · Oct 22
- Freeman Spur Apr 4 · Oct 27
- Cambria Apr 9 · Oct 22
- Elkville Apr 6 · Oct 22
- Carterville Apr 9 · Oct 22
- Herrin Apr 9 · Oct 22
- De Soto Apr 9 · Oct 22
Frequently asked questions
When is the last frost in Royalton, IL?
The median last spring frost in Royalton, IL is April 6. There is still about a 10% chance of frost after April 22, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Royalton, 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 Royalton, IL?
About 199 days between the median last spring frost and first fall frost.
What planting zone is Royalton, IL?
Royalton, IL is in USDA hardiness zone 7a.