Grant Park, IL frost dates
Last spring frostApr 29median date
First fall frostOct 16median date
Growing season170 daysfrost-free
Hardiness zone5bZone 5b
How Grant Park compares
- In 8 years out of 10, the last spring frost in Grant Park falls between April 14 and May 14, a 30-day window. The first fall frost falls between October 3 and October 28.
- The median last frost is 12 days later than the Illinois median of Apr 17.
- Its 170-day growing season is longer than 6% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is typical for zone 5b, where the median is May 1.
- The weather station records an average of 136 nights a year at or below 32°F.
- Compared with Tinley Park, IL, 39 km away, the last frost here is 6 days later than there and the growing season is 10 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 14 |
| 50% (median) | April 29 |
| 10% (safe for tender plants) | May 14 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 3 |
| 50% (median) | October 16 |
| 90% (late) | October 28 |
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 Grant Park, IL
Grant Park, IL frost dates — last frost Apr 29, first frost Oct 16, zone 5b. whenisthelastfrost.com
Crop
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Start indoors: Feb 4 to Feb 18Transplant outside: Apr 1 to Apr 15
Start indoors: Feb 18 to Mar 4Transplant outside: May 13 to May 27
Start indoors: Feb 18 to Mar 4Transplant outside: May 13 to May 27
Start indoors: Mar 4 to Mar 18Transplant outside: May 6 to May 20
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 8 to Apr 22Sow outdoors: Apr 1 to May 6Plant for fall: Aug 21 to Sep 18
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 1 to Apr 15Sow outdoors: Apr 1 to Apr 15Plant for fall: Aug 7 to Aug 28
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 15 to Apr 29Plant for fall: Jul 10 to Jul 31
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 8 to Apr 22Plant for fall: Jul 10 to Jul 31
Start indoors: Mar 4 to Mar 18Transplant outside: Apr 15 to Apr 29Plant for fall: Jul 10 to Jul 31
Start indoors: Mar 18 to Apr 1Transplant outside: May 20 to Jun 3Sow outdoors: May 20 to Jun 3
Start indoors: Mar 18 to Apr 1Transplant outside: May 6 to May 20
Sow outdoors: Mar 18 to Apr 8Plant for fall: Jul 24 to Aug 14
Sow outdoors: Mar 18 to Apr 8Plant for fall: Aug 21 to Sep 11
Sow outdoors: Mar 25 to May 6Plant for fall: Sep 4 to Sep 25
Start indoors: Apr 1 to Apr 8Transplant outside: May 13 to May 20Sow outdoors: May 6 to May 20Plant for fall: Jul 31 to Aug 14
Start indoors: Apr 1 to Apr 8Sow outdoors: May 6 to May 20Plant for fall: Aug 7 to Aug 21
Start indoors: Apr 1 to Apr 8Sow outdoors: May 6 to May 20
Start indoors: Apr 1 to Apr 8Transplant outside: May 13 to May 27
Sow outdoors: Apr 8 to May 6Plant for fall: Jul 24 to Aug 7
Sow outdoors: Apr 8 to May 6Plant for fall: Aug 7 to Aug 21
Sow outdoors: Apr 8 to Apr 29
Sow outdoors: Apr 15 to May 13Plant for fall: Aug 7 to Aug 21
Sow outdoors: Apr 15 to May 6Plant for fall: Aug 21 to Sep 11
Sow outdoors: May 6 to May 27Plant for fall: Jul 31 to Aug 14
Sow outdoors: May 6 to May 20
Transplant outside: May 13 to Jun 3
Plant for fall: Oct 2 to Nov 6
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Grant Park, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 4 – Feb 18 | Apr 1 – Apr 15 | — | — |
| Peppers | Feb 18 – Mar 4 | May 13 – May 27 | — | — |
| Eggplant | Feb 18 – Mar 4 | May 13 – May 27 | — | — |
| Tomatoes | Mar 4 – Mar 18 | May 6 – May 20 | — | — |
| Lettuce | Mar 4 – Mar 18 | Apr 8 – Apr 22 | Apr 1 – May 6 | Aug 21 – Sep 18 |
| Kale | Mar 4 – Mar 18 | Apr 1 – Apr 15 | Apr 1 – Apr 15 | Aug 7 – Aug 28 |
| Broccoli | Mar 4 – Mar 18 | Apr 15 – Apr 29 | — | Jul 10 – Jul 31 |
| Cabbage | Mar 4 – Mar 18 | Apr 8 – Apr 22 | — | Jul 10 – Jul 31 |
| Cauliflower | Mar 4 – Mar 18 | Apr 15 – Apr 29 | — | Jul 10 – Jul 31 |
| Okra | Mar 18 – Apr 1 | May 20 – Jun 3 | May 20 – Jun 3 | — |
| Basil | Mar 18 – Apr 1 | May 6 – May 20 | — | — |
| Peas | — | — | Mar 18 – Apr 8 | Jul 24 – Aug 14 |
| Spinach | — | — | Mar 18 – Apr 8 | Aug 21 – Sep 11 |
| Radishes | — | — | Mar 25 – May 6 | Sep 4 – Sep 25 |
| Cucumbers | Apr 1 – Apr 8 | May 13 – May 20 | May 6 – May 20 | Jul 31 – Aug 14 |
| Zucchini & Summer Squash | Apr 1 – Apr 8 | — | May 6 – May 20 | Aug 7 – Aug 21 |
| Winter Squash & Pumpkins | Apr 1 – Apr 8 | — | May 6 – May 20 | — |
| Melons & Watermelon | Apr 1 – Apr 8 | May 13 – May 27 | — | — |
| Carrots | — | — | Apr 8 – May 6 | Jul 24 – Aug 7 |
| Beets | — | — | Apr 8 – May 6 | Aug 7 – Aug 21 |
| Potatoes | — | — | Apr 8 – Apr 29 | — |
| Swiss Chard | — | — | Apr 15 – May 13 | Aug 7 – Aug 21 |
| Cilantro | — | — | Apr 15 – May 6 | Aug 21 – Sep 11 |
| Green Beans | — | — | May 6 – May 27 | Jul 31 – Aug 14 |
| Sweet Corn | — | — | May 6 – May 20 | — |
| Sweet Potatoes | — | May 13 – Jun 3 | — | — |
| Garlic | — | — | — | Oct 2 – Nov 6 |
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 Lowell, IN weather station, 19 km away (elevation 666 ft (203 m)).
Frost dates near Grant Park
- Momence Apr 19 · Oct 24
- Beecher Apr 23 · Oct 20
- Peotone Apr 23 · Oct 20
- Manteno Apr 19 · Oct 24
- Hopkins Park Apr 19 · Oct 24
- Pembroke Township Apr 19 · Oct 24
- Bradley Apr 19 · Oct 24
- Bourbonnais Apr 19 · Oct 24
- Crete Apr 23 · Oct 20
- Monee Apr 23 · Oct 20
Frequently asked questions
When is the last frost in Grant Park, IL?
The median last spring frost in Grant Park, IL is April 29. There is still about a 10% chance of frost after May 14, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Grant Park, IL?
The median first fall frost is October 16, with about a 10% chance of frost before October 3.
How long is the growing season in Grant Park, IL?
About 170 days between the median last spring frost and first fall frost.
What planting zone is Grant Park, IL?
Grant Park, IL is in USDA hardiness zone 5b.