Brimfield, IL frost dates
Last spring frostApr 22median date
First fall frostOct 14median date
Growing season175 daysfrost-free
Hardiness zone5bZone 5b
How Brimfield compares
- In 8 years out of 10, the last spring frost in Brimfield falls between April 8 and May 6, a 28-day window. The first fall frost falls between September 29 and October 27.
- The median last frost is 5 days later than the Illinois median of Apr 17.
- Its 175-day growing season is longer than 16% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 9 days earlier than the zone 5b median of May 1. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5b chart.
- The weather station records an average of 143 nights a year at or below 32°F.
- Compared with Peoria, IL, 25 km away, the last frost here is 6 days later than there and the growing season is 15 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 8 |
| 50% (median) | April 22 |
| 10% (safe for tender plants) | May 6 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 29 |
| 50% (median) | October 14 |
| 90% (late) | October 27 |
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 Brimfield, IL
Brimfield, IL frost dates — last frost Apr 22, first frost Oct 14, zone 5b. whenisthelastfrost.com
Crop
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Start indoors: Jan 28 to Feb 11Transplant outside: Mar 25 to Apr 8
Start indoors: Feb 11 to Feb 25Transplant outside: May 6 to May 20
Start indoors: Feb 11 to Feb 25Transplant outside: May 6 to May 20
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 29 to May 13
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 1 to Apr 15Sow outdoors: Mar 25 to Apr 29Plant for fall: Aug 19 to Sep 16
Start indoors: Feb 25 to Mar 11Transplant outside: Mar 25 to Apr 8Sow outdoors: Mar 25 to Apr 8Plant for fall: Aug 5 to Aug 26
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 8 to Apr 22Plant for fall: Jul 8 to Jul 29
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 1 to Apr 15Plant for fall: Jul 8 to Jul 29
Start indoors: Feb 25 to Mar 11Transplant outside: Apr 8 to Apr 22Plant for fall: Jul 8 to Jul 29
Start indoors: Mar 11 to Mar 25Transplant outside: May 13 to May 27Sow outdoors: May 13 to May 27
Start indoors: Mar 11 to Mar 25Transplant outside: Apr 29 to May 13
Sow outdoors: Mar 11 to Apr 1Plant for fall: Jul 22 to Aug 12
Sow outdoors: Mar 11 to Apr 1Plant for fall: Aug 19 to Sep 9
Sow outdoors: Mar 18 to Apr 29Plant for fall: Sep 2 to Sep 23
Start indoors: Mar 25 to Apr 1Transplant outside: May 6 to May 13Sow outdoors: Apr 29 to May 13Plant for fall: Jul 29 to Aug 12
Start indoors: Mar 25 to Apr 1Sow outdoors: Apr 29 to May 13Plant for fall: Aug 5 to Aug 19
Start indoors: Mar 25 to Apr 1Sow outdoors: Apr 29 to May 13
Start indoors: Mar 25 to Apr 1Transplant outside: May 6 to May 20
Sow outdoors: Apr 1 to Apr 29Plant for fall: Jul 22 to Aug 5
Sow outdoors: Apr 1 to Apr 29Plant for fall: Aug 5 to Aug 19
Sow outdoors: Apr 1 to Apr 22
Sow outdoors: Apr 8 to May 6Plant for fall: Aug 5 to Aug 19
Sow outdoors: Apr 8 to Apr 29Plant for fall: Aug 19 to Sep 9
Sow outdoors: Apr 29 to May 20Plant for fall: Jul 29 to Aug 12
Sow outdoors: Apr 29 to May 13
Transplant outside: May 6 to May 27
Plant for fall: Sep 30 to Nov 4
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Brimfield, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 28 – Feb 11 | Mar 25 – Apr 8 | — | — |
| Peppers | Feb 11 – Feb 25 | May 6 – May 20 | — | — |
| Eggplant | Feb 11 – Feb 25 | May 6 – May 20 | — | — |
| Tomatoes | Feb 25 – Mar 11 | Apr 29 – May 13 | — | — |
| Lettuce | Feb 25 – Mar 11 | Apr 1 – Apr 15 | Mar 25 – Apr 29 | Aug 19 – Sep 16 |
| Kale | Feb 25 – Mar 11 | Mar 25 – Apr 8 | Mar 25 – Apr 8 | Aug 5 – Aug 26 |
| Broccoli | Feb 25 – Mar 11 | Apr 8 – Apr 22 | — | Jul 8 – Jul 29 |
| Cabbage | Feb 25 – Mar 11 | Apr 1 – Apr 15 | — | Jul 8 – Jul 29 |
| Cauliflower | Feb 25 – Mar 11 | Apr 8 – Apr 22 | — | Jul 8 – Jul 29 |
| Okra | Mar 11 – Mar 25 | May 13 – May 27 | May 13 – May 27 | — |
| Basil | Mar 11 – Mar 25 | Apr 29 – May 13 | — | — |
| Peas | — | — | Mar 11 – Apr 1 | Jul 22 – Aug 12 |
| Spinach | — | — | Mar 11 – Apr 1 | Aug 19 – Sep 9 |
| Radishes | — | — | Mar 18 – Apr 29 | Sep 2 – Sep 23 |
| Cucumbers | Mar 25 – Apr 1 | May 6 – May 13 | Apr 29 – May 13 | Jul 29 – Aug 12 |
| Zucchini & Summer Squash | Mar 25 – Apr 1 | — | Apr 29 – May 13 | Aug 5 – Aug 19 |
| Winter Squash & Pumpkins | Mar 25 – Apr 1 | — | Apr 29 – May 13 | — |
| Melons & Watermelon | Mar 25 – Apr 1 | May 6 – May 20 | — | — |
| Carrots | — | — | Apr 1 – Apr 29 | Jul 22 – Aug 5 |
| Beets | — | — | Apr 1 – Apr 29 | Aug 5 – Aug 19 |
| Potatoes | — | — | Apr 1 – Apr 22 | — |
| Swiss Chard | — | — | Apr 8 – May 6 | Aug 5 – Aug 19 |
| Cilantro | — | — | Apr 8 – Apr 29 | Aug 19 – Sep 9 |
| Green Beans | — | — | Apr 29 – May 20 | Jul 29 – Aug 12 |
| Sweet Corn | — | — | Apr 29 – May 13 | — |
| Sweet Potatoes | — | May 6 – May 27 | — | — |
| Garlic | — | — | — | Sep 30 – Nov 4 |
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 Princeville, IL weather station, 15 km away (elevation 751 ft (229 m)).
Frost dates near Brimfield
- Elmwood Apr 22 · Oct 14
- Laura Apr 22 · Oct 14
- Yates City Apr 21 · Oct 20
- Princeville Apr 22 · Oct 14
- Williamsfield Apr 21 · Oct 20
- Edwards Apr 16 · Oct 23
- Trivoli Apr 16 · Oct 23
- Hanna City Apr 16 · Oct 23
- Farmington Apr 16 · Oct 23
- Dunlap Apr 22 · Oct 14
Frequently asked questions
When is the last frost in Brimfield, IL?
The median last spring frost in Brimfield, IL is April 22. There is still about a 10% chance of frost after May 6, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Brimfield, IL?
The median first fall frost is October 14, with about a 10% chance of frost before September 29.
How long is the growing season in Brimfield, IL?
About 175 days between the median last spring frost and first fall frost.
What planting zone is Brimfield, IL?
Brimfield, IL is in USDA hardiness zone 5b.