Pontiac, IL frost dates
Last spring frostApr 16median date
First fall frostOct 24median date
Growing season191 daysfrost-free
Hardiness zone6aZone 6a
How Pontiac compares
- In 8 years out of 10, the last spring frost in Pontiac falls between April 3 and May 2, a 29-day window. The first fall frost falls between October 12 and November 5.
- The median last frost is 1 day earlier than the Illinois median of Apr 17.
- Its 191-day growing season is longer than 62% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 13 days earlier than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 122 nights a year at or below 32°F.
- Compared with Normal, IL, 51 km away, the last frost here is 9 days earlier than there and the growing season is 17 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 3 |
| 50% (median) | April 16 |
| 10% (safe for tender plants) | May 2 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 12 |
| 50% (median) | October 24 |
| 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 Pontiac, IL
Pontiac, IL frost dates — last frost Apr 16, first frost Oct 24, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Jan 22 to Feb 5Transplant outside: Mar 19 to Apr 2
Start indoors: Feb 5 to Feb 19Transplant outside: Apr 30 to May 14
Start indoors: Feb 5 to Feb 19Transplant outside: Apr 30 to May 14
Start indoors: Feb 19 to Mar 5Transplant outside: Apr 23 to May 7
Start indoors: Feb 19 to Mar 5Transplant outside: Mar 26 to Apr 9Sow outdoors: Mar 19 to Apr 23Plant for fall: Aug 29 to Sep 26
Start indoors: Feb 19 to Mar 5Transplant outside: Mar 19 to Apr 2Sow outdoors: Mar 19 to Apr 2Plant for fall: Aug 15 to Sep 5
Start indoors: Feb 19 to Mar 5Transplant outside: Apr 2 to Apr 16Plant for fall: Jul 18 to Aug 8
Start indoors: Feb 19 to Mar 5Transplant outside: Mar 26 to Apr 9Plant for fall: Jul 18 to Aug 8
Start indoors: Feb 19 to Mar 5Transplant outside: Apr 2 to Apr 16Plant for fall: Jul 18 to Aug 8
Start indoors: Mar 5 to Mar 19Transplant outside: May 7 to May 21Sow outdoors: May 7 to May 21
Start indoors: Mar 5 to Mar 19Transplant outside: Apr 23 to May 7
Sow outdoors: Mar 5 to Mar 26Plant for fall: Aug 1 to Aug 22
Sow outdoors: Mar 5 to Mar 26Plant for fall: Aug 29 to Sep 19
Sow outdoors: Mar 12 to Apr 23Plant for fall: Sep 12 to Oct 3
Start indoors: Mar 19 to Mar 26Transplant outside: Apr 30 to May 7Sow outdoors: Apr 23 to May 7Plant for fall: Aug 8 to Aug 22
Start indoors: Mar 19 to Mar 26Sow outdoors: Apr 23 to May 7Plant for fall: Aug 15 to Aug 29
Start indoors: Mar 19 to Mar 26Sow outdoors: Apr 23 to May 7
Start indoors: Mar 19 to Mar 26Transplant outside: Apr 30 to May 14
Sow outdoors: Mar 26 to Apr 23Plant for fall: Aug 1 to Aug 15
Sow outdoors: Mar 26 to Apr 23Plant for fall: Aug 15 to Aug 29
Sow outdoors: Mar 26 to Apr 16
Sow outdoors: Apr 2 to Apr 30Plant for fall: Aug 15 to Aug 29
Sow outdoors: Apr 2 to Apr 23Plant for fall: Aug 29 to Sep 19
Sow outdoors: Apr 23 to May 14Plant for fall: Aug 8 to Aug 22
Sow outdoors: Apr 23 to May 7
Transplant outside: Apr 30 to May 21
Plant for fall: Oct 10 to Nov 14
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Pontiac, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 22 – Feb 5 | Mar 19 – Apr 2 | — | — |
| Peppers | Feb 5 – Feb 19 | Apr 30 – May 14 | — | — |
| Eggplant | Feb 5 – Feb 19 | Apr 30 – May 14 | — | — |
| Tomatoes | Feb 19 – Mar 5 | Apr 23 – May 7 | — | — |
| Lettuce | Feb 19 – Mar 5 | Mar 26 – Apr 9 | Mar 19 – Apr 23 | Aug 29 – Sep 26 |
| Kale | Feb 19 – Mar 5 | Mar 19 – Apr 2 | Mar 19 – Apr 2 | Aug 15 – Sep 5 |
| Broccoli | Feb 19 – Mar 5 | Apr 2 – Apr 16 | — | Jul 18 – Aug 8 |
| Cabbage | Feb 19 – Mar 5 | Mar 26 – Apr 9 | — | Jul 18 – Aug 8 |
| Cauliflower | Feb 19 – Mar 5 | Apr 2 – Apr 16 | — | Jul 18 – Aug 8 |
| Okra | Mar 5 – Mar 19 | May 7 – May 21 | May 7 – May 21 | — |
| Basil | Mar 5 – Mar 19 | Apr 23 – May 7 | — | — |
| Peas | — | — | Mar 5 – Mar 26 | Aug 1 – Aug 22 |
| Spinach | — | — | Mar 5 – Mar 26 | Aug 29 – Sep 19 |
| Radishes | — | — | Mar 12 – Apr 23 | Sep 12 – Oct 3 |
| Cucumbers | Mar 19 – Mar 26 | Apr 30 – May 7 | Apr 23 – May 7 | Aug 8 – Aug 22 |
| Zucchini & Summer Squash | Mar 19 – Mar 26 | — | Apr 23 – May 7 | Aug 15 – Aug 29 |
| Winter Squash & Pumpkins | Mar 19 – Mar 26 | — | Apr 23 – May 7 | — |
| Melons & Watermelon | Mar 19 – Mar 26 | Apr 30 – May 14 | — | — |
| Carrots | — | — | Mar 26 – Apr 23 | Aug 1 – Aug 15 |
| Beets | — | — | Mar 26 – Apr 23 | Aug 15 – Aug 29 |
| Potatoes | — | — | Mar 26 – Apr 16 | — |
| Swiss Chard | — | — | Apr 2 – Apr 30 | Aug 15 – Aug 29 |
| Cilantro | — | — | Apr 2 – Apr 23 | Aug 29 – Sep 19 |
| Green Beans | — | — | Apr 23 – May 14 | Aug 8 – Aug 22 |
| Sweet Corn | — | — | Apr 23 – May 7 | — |
| Sweet Potatoes | — | Apr 30 – May 21 | — | — |
| Garlic | — | — | — | Oct 10 – Nov 14 |
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 Pontiac, IL weather station, about 1 km away (elevation 650 ft (198 m)).
Frost dates near Pontiac
- Graymont Apr 16 · Oct 24
- Chenoa Apr 23 · Oct 15
- Fairbury Apr 23 · Oct 15
- Saunemin Apr 16 · Oct 24
- Odell Apr 27 · Oct 15
- Flanagan Apr 26 · Oct 17
- Cornell Apr 12 · Oct 28
- Blackstone Apr 12 · Oct 28
- Forrest Apr 25 · Oct 20
- Long Point Apr 12 · Oct 28
Frequently asked questions
When is the last frost in Pontiac, IL?
The median last spring frost in Pontiac, IL is April 16. There is still about a 10% chance of frost after May 2, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Pontiac, IL?
The median first fall frost is October 24, with about a 10% chance of frost before October 12.
How long is the growing season in Pontiac, IL?
About 191 days between the median last spring frost and first fall frost.
What planting zone is Pontiac, IL?
Pontiac, IL is in USDA hardiness zone 6a.