Cambridge, IL frost dates
Last spring frostApr 20median date
First fall frostOct 20median date
Growing season183 daysfrost-free
Hardiness zone5bZone 5b
How Cambridge compares
- In 8 years out of 10, the last spring frost in Cambridge falls between April 6 and May 6, a 30-day window. The first fall frost falls between October 5 and October 31.
- The median last frost is 3 days later than the Illinois median of Apr 17.
- Its 183-day growing season is longer than 40% of the 1,287 Illinois places with a regular frost season (state median 187 days).
- The last frost is 11 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 126 nights a year at or below 32°F.
- Compared with Davenport, IA, 44 km away, the last frost here is 3 days earlier than there and the growing season is 8 days longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 6 |
| 50% (median) | April 20 |
| 10% (safe for tender plants) | May 6 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 5 |
| 50% (median) | October 20 |
| 90% (late) | October 31 |
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 Cambridge, IL
Cambridge, IL frost dates — last frost Apr 20, first frost Oct 20, zone 5b. whenisthelastfrost.com
Crop
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Start indoors: Jan 26 to Feb 9Transplant outside: Mar 23 to Apr 6
Start indoors: Feb 9 to Feb 23Transplant outside: May 4 to May 18
Start indoors: Feb 9 to Feb 23Transplant outside: May 4 to May 18
Start indoors: Feb 23 to Mar 9Transplant outside: Apr 27 to May 11
Start indoors: Feb 23 to Mar 9Transplant outside: Mar 30 to Apr 13Sow outdoors: Mar 23 to Apr 27Plant for fall: Aug 25 to Sep 22
Start indoors: Feb 23 to Mar 9Transplant outside: Mar 23 to Apr 6Sow outdoors: Mar 23 to Apr 6Plant for fall: Aug 11 to Sep 1
Start indoors: Feb 23 to Mar 9Transplant outside: Apr 6 to Apr 20Plant for fall: Jul 14 to Aug 4
Start indoors: Feb 23 to Mar 9Transplant outside: Mar 30 to Apr 13Plant for fall: Jul 14 to Aug 4
Start indoors: Feb 23 to Mar 9Transplant outside: Apr 6 to Apr 20Plant for fall: Jul 14 to Aug 4
Start indoors: Mar 9 to Mar 23Transplant outside: May 11 to May 25Sow outdoors: May 11 to May 25
Start indoors: Mar 9 to Mar 23Transplant outside: Apr 27 to May 11
Sow outdoors: Mar 9 to Mar 30Plant for fall: Jul 28 to Aug 18
Sow outdoors: Mar 9 to Mar 30Plant for fall: Aug 25 to Sep 15
Sow outdoors: Mar 16 to Apr 27Plant for fall: Sep 8 to Sep 29
Start indoors: Mar 23 to Mar 30Transplant outside: May 4 to May 11Sow outdoors: Apr 27 to May 11Plant for fall: Aug 4 to Aug 18
Start indoors: Mar 23 to Mar 30Sow outdoors: Apr 27 to May 11Plant for fall: Aug 11 to Aug 25
Start indoors: Mar 23 to Mar 30Sow outdoors: Apr 27 to May 11
Start indoors: Mar 23 to Mar 30Transplant outside: May 4 to May 18
Sow outdoors: Mar 30 to Apr 27Plant for fall: Jul 28 to Aug 11
Sow outdoors: Mar 30 to Apr 27Plant for fall: Aug 11 to Aug 25
Sow outdoors: Mar 30 to Apr 20
Sow outdoors: Apr 6 to May 4Plant for fall: Aug 11 to Aug 25
Sow outdoors: Apr 6 to Apr 27Plant for fall: Aug 25 to Sep 15
Sow outdoors: Apr 27 to May 18Plant for fall: Aug 4 to Aug 18
Sow outdoors: Apr 27 to May 11
Transplant outside: May 4 to May 25
Plant for fall: Oct 6 to Nov 10
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Cambridge, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Jan 26 – Feb 9 | Mar 23 – Apr 6 | — | — |
| Peppers | Feb 9 – Feb 23 | May 4 – May 18 | — | — |
| Eggplant | Feb 9 – Feb 23 | May 4 – May 18 | — | — |
| Tomatoes | Feb 23 – Mar 9 | Apr 27 – May 11 | — | — |
| Lettuce | Feb 23 – Mar 9 | Mar 30 – Apr 13 | Mar 23 – Apr 27 | Aug 25 – Sep 22 |
| Kale | Feb 23 – Mar 9 | Mar 23 – Apr 6 | Mar 23 – Apr 6 | Aug 11 – Sep 1 |
| Broccoli | Feb 23 – Mar 9 | Apr 6 – Apr 20 | — | Jul 14 – Aug 4 |
| Cabbage | Feb 23 – Mar 9 | Mar 30 – Apr 13 | — | Jul 14 – Aug 4 |
| Cauliflower | Feb 23 – Mar 9 | Apr 6 – Apr 20 | — | Jul 14 – Aug 4 |
| Okra | Mar 9 – Mar 23 | May 11 – May 25 | May 11 – May 25 | — |
| Basil | Mar 9 – Mar 23 | Apr 27 – May 11 | — | — |
| Peas | — | — | Mar 9 – Mar 30 | Jul 28 – Aug 18 |
| Spinach | — | — | Mar 9 – Mar 30 | Aug 25 – Sep 15 |
| Radishes | — | — | Mar 16 – Apr 27 | Sep 8 – Sep 29 |
| Cucumbers | Mar 23 – Mar 30 | May 4 – May 11 | Apr 27 – May 11 | Aug 4 – Aug 18 |
| Zucchini & Summer Squash | Mar 23 – Mar 30 | — | Apr 27 – May 11 | Aug 11 – Aug 25 |
| Winter Squash & Pumpkins | Mar 23 – Mar 30 | — | Apr 27 – May 11 | — |
| Melons & Watermelon | Mar 23 – Mar 30 | May 4 – May 18 | — | — |
| Carrots | — | — | Mar 30 – Apr 27 | Jul 28 – Aug 11 |
| Beets | — | — | Mar 30 – Apr 27 | Aug 11 – Aug 25 |
| Potatoes | — | — | Mar 30 – Apr 20 | — |
| Swiss Chard | — | — | Apr 6 – May 4 | Aug 11 – Aug 25 |
| Cilantro | — | — | Apr 6 – Apr 27 | Aug 25 – Sep 15 |
| Green Beans | — | — | Apr 27 – May 18 | Aug 4 – Aug 18 |
| Sweet Corn | — | — | Apr 27 – May 11 | — |
| Sweet Potatoes | — | May 4 – May 25 | — | — |
| Garlic | — | — | — | Oct 6 – Nov 10 |
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 Geneseo, IL weather station, 16 km away (elevation 640 ft (195 m)).
Frost dates near Cambridge
- Andover Apr 20 · Oct 20
- Osco Apr 20 · Oct 20
- Lynn Center Apr 28 · Oct 12
- Bishop Hill Apr 26 · Oct 12
- Woodhull Apr 28 · Oct 12
- Geneseo Apr 20 · Oct 20
- Atkinson Apr 20 · Oct 20
- Orion Apr 24 · Oct 18
- Ophiem Apr 28 · Oct 12
- Galva Apr 26 · Oct 12
Frequently asked questions
When is the last frost in Cambridge, IL?
The median last spring frost in Cambridge, IL is April 20. 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 Cambridge, IL?
The median first fall frost is October 20, with about a 10% chance of frost before October 5.
How long is the growing season in Cambridge, IL?
About 183 days between the median last spring frost and first fall frost.
What planting zone is Cambridge, IL?
Cambridge, IL is in USDA hardiness zone 5b.