Frost dates for 60659Chicago, IL
The average last spring frost in Chicago is April 26 and the average first fall frost is October 21, giving a typical growing season of about 176 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 26
- Average first fall frost
- Oct 21
- Growing season
- 176 days
Safer after May 11 (1-in-10 risk)
Possible by Oct 5 (1-in-10 risk)
Last frost typically in 181 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | Apr 24 · May 8 · May 26 | Sep 28 · Oct 10 · Oct 24 | 154 days | 100% |
| Frost / freeze (32°F) | Apr 11 · Apr 26 · May 11 | Oct 5 · Oct 21 · Nov 2 | 176 days | 100% |
| Hard freeze (28°F) | Mar 31 · Apr 13 · Apr 28 | Oct 17 · Nov 1 · Nov 14 | 202 days | 100% |
Planting calendar for Chicago
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Mar 26 – Jun 1 |
| Tomatoes | Transplant outdoors | May 12 – Jul 1 |
| Peppers | Start seeds indoors | Mar 26 – Apr 26 |
| Peppers | Transplant outdoors | May 26 – Jun 26 |
| Eggplant | Start seeds indoors | Apr 12 – May 11 |
| Eggplant | Transplant outdoors | May 26 – Jun 26 |
| Cucumbers | Sow outdoors | May 26 – Jul 11 |
| Summer squash | Sow outdoors | May 12 – Jun 26 |
| Winter squash & pumpkins | Sow outdoors | May 26 – Jun 26 |
| Snap beans | Sow outdoors | May 12 – Aug 3 |
| Sweet corn | Sow outdoors | May 12 – Jul 1 |
| Watermelon & cantaloupe | Sow outdoors | May 26 – Jun 26 |
| Okra | Sow outdoors | May 19 – Jun 11 |
| Peas | Sow outdoors (spring) | Mar 26 – May 11 |
| Potatoes | Plant outdoors (spring) | Mar 26 – May 26 |
| Onions | Start seeds indoors (spring) | Feb 12 – Mar 11 |
| Onions | Transplant outdoors (spring) | Apr 12 – May 11 |
| Broccoli | Start seeds indoors (spring) | Mar 8 – Apr 11 |
| Broccoli | Transplant outdoors (spring) | Apr 12 – May 11 |
| Broccoli | Start seeds indoors (fall) | Jun 21 – Jul 1 |
| Broccoli | Transplant outdoors (fall) | Jul 21 – Aug 1 |
| Cabbage | Start seeds indoors (spring) | Feb 26 – Mar 26 |
| Cabbage | Transplant outdoors (spring) | Mar 26 – Apr 26 |
| Cabbage | Start seeds indoors (fall) | Jun 11 – Jul 11 |
| Cabbage | Transplant outdoors (fall) | Jul 11 – Aug 11 |
| Leaf lettuce | Sow outdoors (spring) | Mar 26 – Jun 11 |
| Leaf lettuce | Sow outdoors (fall) | Jul 11 – Aug 27 |
| Spinach | Sow outdoors (spring) | Mar 19 – May 2 |
| Spinach | Sow outdoors (fall) | Jul 28 – Sep 1 |
| Radishes | Sow outdoors (spring) | Mar 26 – May 16 |
| Radishes | Sow outdoors (fall) | Jul 11 – Sep 11 |
| Kale | Sow outdoors (spring) | Apr 12 – May 2 |
| Kale | Sow outdoors (fall) | Jul 4 – Aug 11 |
| Carrots | Sow outdoors (spring) | Apr 26 – Jun 11 |
| Carrots | Sow outdoors (fall) | Jun 11 – Jul 27 |
| Garlic | Plant outdoors (fall) | Oct 11 – Nov 11 |
Where these dates come from
ZIP code 60659 is matched to the NOAA station Chicago Botanic Garden, IL, 16.9 km away, at 630 ft elevation (33 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Chicago Botanic Garden, IL (used) | 630 ft | Apr 26 | Oct 21 |
| Chicago Ohare Intl Ap, IL | 658 ft | Apr 16 | Oct 28 |
| Chicago Northerly Is, IL | 583 ft | Apr 10 | Nov 5 |
| Chicago Palwaukee Ap, IL | 636 ft | Apr 19 | Oct 26 |
Frost dates near Chicago
- Lincolnwood, IL 60712 · last Apr 26, first Oct 21
- Chicago, IL 60645 · last Apr 26, first Oct 21
- Evanston, IL 60202 · last Apr 26, first Oct 21
- Skokie, IL 60076 · last Apr 26, first Oct 21
- Morton Grove, IL 60053 · last Apr 26, first Oct 21
- Niles, IL 60714 · last Apr 16, first Oct 28
- Wilmette, IL 60091 · last Apr 26, first Oct 21
- Harwood Heights, IL 60706 · last Apr 16, first Oct 28
Frequently asked questions
- When is the last frost in Chicago, IL?
- For ZIP code 60659, the average last spring frost (32°F) is April 26, based on NOAA 1991-2020 climate normals for the Chicago Botanic Garden, IL weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Chicago, IL?
- The average first fall frost (32°F) is October 21. There is a 1-in-10 chance of frost by October 5, so tender plants are at risk from that point on.
- How long is the growing season in 60659?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 176 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.