Brussels, IL frost dates
Last spring frostApr 5median date
First fall frostOct 27median date
Growing season205 daysfrost-free
Hardiness zone6bZone 6b
How Brussels compares
- In 8 years out of 10, the last spring frost in Brussels falls between March 22 and April 21, a 30-day window. The first fall frost falls between October 13 and November 9.
- The median last frost is 12 days earlier than the Illinois median of Apr 17.
- Its 205-day growing season is longer than 90% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 17 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 102 nights a year at or below 32°F.
- Compared with Saint Peters, MO, 19 km away, the last frost here is 4 days earlier than there and the growing season is 5 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | March 22 |
| 50% (median) | April 5 |
| 10% (safe for tender plants) | April 21 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 13 |
| 50% (median) | October 27 |
| 90% (late) | November 9 |
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 Brussels, IL
Brussels, IL frost dates — last frost Apr 5, first frost Oct 27, zone 6b. whenisthelastfrost.com
Crop
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Start indoors: Jan 11 to Jan 25Transplant outside: Mar 8 to Mar 22
Start indoors: Jan 25 to Feb 8Transplant outside: Apr 19 to May 3
Start indoors: Jan 25 to Feb 8Transplant outside: Apr 19 to May 3
Start indoors: Feb 8 to Feb 22Transplant outside: Apr 12 to Apr 26
Start indoors: Feb 8 to Feb 22Transplant outside: Mar 15 to Mar 29Sow outdoors: Mar 8 to Apr 12Plant for fall: Sep 1 to Sep 29
Start indoors: Feb 8 to Feb 22Transplant outside: Mar 8 to Mar 22Sow outdoors: Mar 8 to Mar 22Plant for fall: Aug 18 to Sep 8
Start indoors: Feb 8 to Feb 22Transplant outside: Mar 22 to Apr 5Plant for fall: Jul 21 to Aug 11
Start indoors: Feb 8 to Feb 22Transplant outside: Mar 15 to Mar 29Plant for fall: Jul 21 to Aug 11
Start indoors: Feb 8 to Feb 22Transplant outside: Mar 22 to Apr 5Plant for fall: Jul 21 to Aug 11
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 26 to May 10Sow outdoors: Apr 26 to May 10
Start indoors: Feb 22 to Mar 8Transplant outside: Apr 12 to Apr 26
Sow outdoors: Feb 22 to Mar 15Plant for fall: Aug 4 to Aug 25
Sow outdoors: Feb 22 to Mar 15Plant for fall: Sep 1 to Sep 22
Sow outdoors: Mar 1 to Apr 12Plant for fall: Sep 15 to Oct 6
Start indoors: Mar 8 to Mar 15Transplant outside: Apr 19 to Apr 26Sow outdoors: Apr 12 to Apr 26Plant for fall: Aug 11 to Aug 25
Start indoors: Mar 8 to Mar 15Sow outdoors: Apr 12 to Apr 26Plant for fall: Aug 18 to Sep 1
Start indoors: Mar 8 to Mar 15Sow outdoors: Apr 12 to Apr 26
Start indoors: Mar 8 to Mar 15Transplant outside: Apr 19 to May 3
Sow outdoors: Mar 15 to Apr 12Plant for fall: Aug 4 to Aug 18
Sow outdoors: Mar 15 to Apr 12Plant for fall: Aug 18 to Sep 1
Sow outdoors: Mar 15 to Apr 5
Sow outdoors: Mar 22 to Apr 19Plant for fall: Aug 18 to Sep 1
Sow outdoors: Mar 22 to Apr 12Plant for fall: Sep 1 to Sep 22
Sow outdoors: Apr 12 to May 3Plant for fall: Aug 11 to Aug 25
Sow outdoors: Apr 12 to Apr 26
Transplant outside: Apr 19 to May 10
Plant for fall: Oct 13 to Nov 17
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Brussels, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 11 – Jan 25 | Mar 8 – Mar 22 | — | — |
| Peppers | Jan 25 – Feb 8 | Apr 19 – May 3 | — | — |
| Eggplant | Jan 25 – Feb 8 | Apr 19 – May 3 | — | — |
| Tomatoes | Feb 8 – Feb 22 | Apr 12 – Apr 26 | — | — |
| Lettuce | Feb 8 – Feb 22 | Mar 15 – Mar 29 | Mar 8 – Apr 12 | Sep 1 – Sep 29 |
| Kale | Feb 8 – Feb 22 | Mar 8 – Mar 22 | Mar 8 – Mar 22 | Aug 18 – Sep 8 |
| Broccoli | Feb 8 – Feb 22 | Mar 22 – Apr 5 | — | Jul 21 – Aug 11 |
| Cabbage | Feb 8 – Feb 22 | Mar 15 – Mar 29 | — | Jul 21 – Aug 11 |
| Cauliflower | Feb 8 – Feb 22 | Mar 22 – Apr 5 | — | Jul 21 – Aug 11 |
| Okra | Feb 22 – Mar 8 | Apr 26 – May 10 | Apr 26 – May 10 | — |
| Basil | Feb 22 – Mar 8 | Apr 12 – Apr 26 | — | — |
| Peas | — | — | Feb 22 – Mar 15 | Aug 4 – Aug 25 |
| Spinach | — | — | Feb 22 – Mar 15 | Sep 1 – Sep 22 |
| Radishes | — | — | Mar 1 – Apr 12 | Sep 15 – Oct 6 |
| Cucumbers | Mar 8 – Mar 15 | Apr 19 – Apr 26 | Apr 12 – Apr 26 | Aug 11 – Aug 25 |
| Zucchini & Summer Squash | Mar 8 – Mar 15 | — | Apr 12 – Apr 26 | Aug 18 – Sep 1 |
| Winter Squash & Pumpkins | Mar 8 – Mar 15 | — | Apr 12 – Apr 26 | — |
| Melons & Watermelon | Mar 8 – Mar 15 | Apr 19 – May 3 | — | — |
| Carrots | — | — | Mar 15 – Apr 12 | Aug 4 – Aug 18 |
| Beets | — | — | Mar 15 – Apr 12 | Aug 18 – Sep 1 |
| Potatoes | — | — | Mar 15 – Apr 5 | — |
| Swiss Chard | — | — | Mar 22 – Apr 19 | Aug 18 – Sep 1 |
| Cilantro | — | — | Mar 22 – Apr 12 | Sep 1 – Sep 22 |
| Green Beans | — | — | Apr 12 – May 3 | Aug 11 – Aug 25 |
| Sweet Corn | — | — | Apr 12 – Apr 26 | — |
| Sweet Potatoes | — | Apr 19 – May 10 | — | — |
| Garlic | — | — | — | Oct 13 – Nov 17 |
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 St Charles Co Ap, MO weather station, 14 km away (elevation 436 ft (133 m)).
Frost dates near Brussels
- Golden Eagle Apr 8 · Oct 29
- Grafton Apr 5 · Oct 27
- Batchtown Apr 20 · Oct 20
- Fieldon Apr 14 · Oct 19
- Elsah Apr 5 · Oct 27
- Hardin Apr 20 · Oct 20
- Dow Apr 14 · Oct 19
- Jerseyville Apr 14 · Oct 19
- Michael Apr 20 · Oct 20
- Hamburg Apr 20 · Oct 20
Frequently asked questions
When is the last frost in Brussels, IL?
The median last spring frost in Brussels, IL is April 5. There is still about a 10% chance of frost after April 21, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Brussels, IL?
The median first fall frost is October 27, with about a 10% chance of frost before October 13.
How long is the growing season in Brussels, IL?
About 205 days between the median last spring frost and first fall frost.
What planting zone is Brussels, IL?
Brussels, IL is in USDA hardiness zone 6b.