Frost dates for 61702Bloomington, IL
The average last spring frost in Bloomington is April 25 and the average first fall frost is October 16, giving a typical growing season of about 172 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 25
- Average first fall frost
- Oct 16
- Growing season
- 172 days
Safer after May 11 (1-in-10 risk)
Possible by Oct 2 (1-in-10 risk)
Last frost typically in 175 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 21 · May 4 · May 22 | Sep 23 · Oct 5 · Oct 18 | 153 days | 100% |
| Frost / freeze (32°F) | Apr 11 · Apr 25 · May 11 | Oct 2 · Oct 16 · Oct 29 | 172 days | 100% |
| Hard freeze (28°F) | Apr 1 · Apr 14 · May 1 | Oct 12 · Oct 27 · Nov 12 | 195 days | 100% |
Planting calendar for Bloomington
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 25 – May 31 |
| Tomatoes | Transplant outdoors | May 11 – Jun 26 |
| Peppers | Start seeds indoors | Mar 25 – Apr 25 |
| Peppers | Transplant outdoors | May 25 – Jun 25 |
| Eggplant | Start seeds indoors | Apr 11 – May 10 |
| Eggplant | Transplant outdoors | May 25 – Jun 25 |
| Cucumbers | Sow outdoors | May 25 – Jul 6 |
| Summer squash | Sow outdoors | May 11 – Jun 25 |
| Winter squash & pumpkins | Sow outdoors | May 25 – Jun 25 |
| Snap beans | Sow outdoors | May 11 – Jul 29 |
| Sweet corn | Sow outdoors | May 11 – Jun 26 |
| Watermelon & cantaloupe | Sow outdoors | May 25 – Jun 25 |
| Okra | Sow outdoors | May 18 – Jun 10 |
| Peas | Sow outdoors (spring) | Mar 25 – May 10 |
| Potatoes | Plant outdoors (spring) | Mar 25 – May 25 |
| Onions | Start seeds indoors (spring) | Feb 11 – Mar 10 |
| Onions | Transplant outdoors (spring) | Apr 11 – May 10 |
| Broccoli | Start seeds indoors (spring) | Mar 7 – Apr 10 |
| Broccoli | Transplant outdoors (spring) | Apr 11 – May 10 |
| Broccoli | Start seeds indoors (fall) | Jun 16 – Jun 26 |
| Broccoli | Transplant outdoors (fall) | Jul 16 – Jul 27 |
| Cabbage | Start seeds indoors (spring) | Feb 25 – Mar 25 |
| Cabbage | Transplant outdoors (spring) | Mar 25 – Apr 25 |
| Cabbage | Start seeds indoors (fall) | Jun 6 – Jul 6 |
| Cabbage | Transplant outdoors (fall) | Jul 6 – Aug 6 |
| Leaf lettuce | Sow outdoors (spring) | Mar 25 – Jun 10 |
| Leaf lettuce | Sow outdoors (fall) | Jul 6 – Aug 22 |
| Spinach | Sow outdoors (spring) | Mar 18 – May 1 |
| Spinach | Sow outdoors (fall) | Jul 23 – Aug 27 |
| Radishes | Sow outdoors (spring) | Mar 25 – May 15 |
| Radishes | Sow outdoors (fall) | Jul 6 – Sep 6 |
| Kale | Sow outdoors (spring) | Apr 11 – May 1 |
| Kale | Sow outdoors (fall) | Jun 29 – Aug 6 |
| Carrots | Sow outdoors (spring) | Apr 25 – Jun 10 |
| Carrots | Sow outdoors (fall) | Jun 6 – Jul 22 |
| Garlic | Plant outdoors (fall) | Oct 6 – Nov 6 |
Where these dates come from
ZIP code 61702 is matched to the NOAA station Normal 4Ne, IL, 8 km away, at 790 ft elevation (27 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Normal 4Ne, IL (used) | 790 ft | Apr 25 | Oct 16 |
| Bloomington 5W, IL | 852 ft | Apr 21 | Oct 20 |
| Chenoa, IL | 719 ft | Apr 23 | Oct 15 |
| Congerville 2Nw, IL | 640 ft | Apr 21 | Oct 17 |
Frost dates near Bloomington
- Bloomington, IL 61791 · last Apr 25, first Oct 16
- Merna, IL 61758 · last Apr 25, first Oct 16
- Towanda, IL 61776 · last Apr 25, first Oct 16
- Normal, IL 61761 · last Apr 25, first Oct 16
- Cooksville, IL 61730 · last Apr 25, first Oct 16
- Downs, IL 61736 · last Apr 25, first Oct 16
- Ellsworth, IL 61737 · last Apr 25, first Oct 16
- Lexington, IL 61753 · last Apr 23, first Oct 15
Frequently asked questions
- When is the last frost in Bloomington, IL?
- For ZIP code 61702, the average last spring frost (32°F) is April 25, based on NOAA 1991-2020 climate normals for the Normal 4Ne, IL weather station. There is a 1-in-10 chance of a frost after May 11.
- When is the first frost in Bloomington, IL?
- The average first fall frost (32°F) is October 16. There is a 1-in-10 chance of frost by October 2, so tender plants are at risk from that point on.
- How long is the growing season in 61702?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 172 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.