Bishop Hill, IL frost dates
How Bishop Hill compares
- In 8 years out of 10, the last spring frost in Bishop Hill falls between April 12 and May 11, a 29-day window. The first fall frost falls between September 25 and October 24.
- The median last frost is 9 days later than the Illinois median of Apr 17.
- Its 169-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 5 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 137 nights a year at or below 32°F.
- Compared with Davenport, IA, 57 km away, the last frost here is 3 days later than there and the growing season is 6 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 12 |
| 50% (median) | April 26 |
| 10% (safe for tender plants) | May 11 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 25 |
| 50% (median) | October 12 |
| 90% (late) | October 24 |
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 Bishop Hill, IL
Bishop Hill, IL frost dates — last frost Apr 26, first frost Oct 12, zone 5b. whenisthelastfrost.com
When to plant vegetables in Bishop Hill, IL
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 1 – Feb 15 | Mar 29 – Apr 12 | — | — |
| Peppers | Feb 15 – Mar 1 | May 10 – May 24 | — | — |
| Eggplant | Feb 15 – Mar 1 | May 10 – May 24 | — | — |
| Tomatoes | Mar 1 – Mar 15 | May 3 – May 17 | — | — |
| Lettuce | Mar 1 – Mar 15 | Apr 5 – Apr 19 | Mar 29 – May 3 | Aug 17 – Sep 14 |
| Kale | Mar 1 – Mar 15 | Mar 29 – Apr 12 | Mar 29 – Apr 12 | Aug 3 – Aug 24 |
| Broccoli | Mar 1 – Mar 15 | Apr 12 – Apr 26 | — | Jul 6 – Jul 27 |
| Cabbage | Mar 1 – Mar 15 | Apr 5 – Apr 19 | — | Jul 6 – Jul 27 |
| Cauliflower | Mar 1 – Mar 15 | Apr 12 – Apr 26 | — | Jul 6 – Jul 27 |
| Okra | Mar 15 – Mar 29 | May 17 – May 31 | May 17 – May 31 | — |
| Basil | Mar 15 – Mar 29 | May 3 – May 17 | — | — |
| Peas | — | — | Mar 15 – Apr 5 | Jul 20 – Aug 10 |
| Spinach | — | — | Mar 15 – Apr 5 | Aug 17 – Sep 7 |
| Radishes | — | — | Mar 22 – May 3 | Aug 31 – Sep 21 |
| Cucumbers | Mar 29 – Apr 5 | May 10 – May 17 | May 3 – May 17 | Jul 27 – Aug 10 |
| Zucchini & Summer Squash | Mar 29 – Apr 5 | — | May 3 – May 17 | Aug 3 – Aug 17 |
| Winter Squash & Pumpkins | Mar 29 – Apr 5 | — | May 3 – May 17 | — |
| Melons & Watermelon | Mar 29 – Apr 5 | May 10 – May 24 | — | — |
| Carrots | — | — | Apr 5 – May 3 | Jul 20 – Aug 3 |
| Beets | — | — | Apr 5 – May 3 | Aug 3 – Aug 17 |
| Potatoes | — | — | Apr 5 – Apr 26 | — |
| Swiss Chard | — | — | Apr 12 – May 10 | Aug 3 – Aug 17 |
| Cilantro | — | — | Apr 12 – May 3 | Aug 17 – Sep 7 |
| Green Beans | — | — | May 3 – May 24 | Jul 27 – Aug 10 |
| Sweet Corn | — | — | May 3 – May 17 | — |
| Sweet Potatoes | — | May 10 – May 31 | — | — |
| Garlic | — | — | — | Sep 28 – Nov 2 |
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 Galva, IL weather station, 7 km away (elevation 810 ft (247 m)).
Frost dates near Bishop Hill
- Galva Apr 26 · Oct 12
- Altona Apr 28 · Oct 12
- Cambridge Apr 20 · Oct 20
- Woodhull Apr 28 · Oct 12
- Oneida Apr 28 · Oct 12
- Kewanee Apr 24 · Oct 17
- La Fayette Apr 26 · Oct 12
- Andover Apr 20 · Oct 20
- Victoria Apr 28 · Oct 12
- Lynn Center Apr 28 · Oct 12
Frequently asked questions
When is the last frost in Bishop Hill, IL?
The median last spring frost in Bishop Hill, IL is April 26. There is still about a 10% chance of frost after May 11, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Bishop Hill, IL?
The median first fall frost is October 12, with about a 10% chance of frost before September 25.
How long is the growing season in Bishop Hill, IL?
About 169 days between the median last spring frost and first fall frost.
What planting zone is Bishop Hill, IL?
Bishop Hill, IL is in USDA hardiness zone 5b.