Frost dates for 61377Wenona, IL
The average last spring frost in Wenona is April 26 and the average first fall frost is October 17, giving a typical growing season of about 173 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 26
- Average first fall frost
- Oct 17
- Growing season
- 173 days
Safer after May 10 (1-in-10 risk)
Possible by Oct 1 (1-in-10 risk)
Last frost typically in 178 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 5 · May 20 | Sep 23 · Oct 6 · Oct 20 | 154 days | 100% |
| Frost / freeze (32°F) | Apr 11 · Apr 26 · May 10 | Oct 1 · Oct 17 · Oct 29 | 173 days | 100% |
| Hard freeze (28°F) | Apr 1 · Apr 15 · May 1 | Oct 14 · Oct 28 · Nov 9 | 195 days | 100% |
Planting calendar for Wenona
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 – Jun 27 |
| 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 7 |
| Summer squash | Sow outdoors | May 12 – Jun 26 |
| Winter squash & pumpkins | Sow outdoors | May 26 – Jun 26 |
| Snap beans | Sow outdoors | May 12 – Jul 30 |
| Sweet corn | Sow outdoors | May 12 – Jun 27 |
| 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 17 – Jun 27 |
| Broccoli | Transplant outdoors (fall) | Jul 17 – Jul 28 |
| Cabbage | Start seeds indoors (spring) | Feb 26 – Mar 26 |
| Cabbage | Transplant outdoors (spring) | Mar 26 – Apr 26 |
| Cabbage | Start seeds indoors (fall) | Jun 7 – Jul 7 |
| Cabbage | Transplant outdoors (fall) | Jul 7 – Aug 7 |
| Leaf lettuce | Sow outdoors (spring) | Mar 26 – Jun 11 |
| Leaf lettuce | Sow outdoors (fall) | Jul 7 – Aug 23 |
| Spinach | Sow outdoors (spring) | Mar 19 – May 2 |
| Spinach | Sow outdoors (fall) | Jul 24 – Aug 28 |
| Radishes | Sow outdoors (spring) | Mar 26 – May 16 |
| Radishes | Sow outdoors (fall) | Jul 7 – Sep 7 |
| Kale | Sow outdoors (spring) | Apr 12 – May 2 |
| Kale | Sow outdoors (fall) | Jun 30 – Aug 7 |
| Carrots | Sow outdoors (spring) | Apr 26 – Jun 11 |
| Carrots | Sow outdoors (fall) | Jun 7 – Jul 23 |
| Garlic | Plant outdoors (fall) | Oct 7 – Nov 7 |
Where these dates come from
ZIP code 61377 is matched to the NOAA station Minonk, IL, 15.8 km away, at 750 ft elevation (68 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Minonk, IL (used) | 750 ft | Apr 26 | Oct 17 |
| Streator 3 Se, IL | 610 ft | Apr 12 | Oct 28 |
| Lacon, IL | 458 ft | Apr 20 | Oct 17 |
| Ottawa 5Sw, IL | 525 ft | Apr 20 | Oct 22 |
Frost dates near Wenona
- Rutland, IL 61358 · last Apr 26, first Oct 17
- Toluca, IL 61369 · last Apr 26, first Oct 17
- Lostant, IL 61334 · last Apr 24, first Oct 18
- Dana, IL 61321 · last Apr 26, first Oct 17
- Ancona, IL 61311 · last Apr 12, first Oct 28
- Long Point, IL 61333 · last Apr 26, first Oct 17
- Leonore, IL 61332 · last Apr 24, first Oct 18
- Magnolia, IL 61336 · last Apr 24, first Oct 17
Frequently asked questions
- When is the last frost in Wenona, IL?
- For ZIP code 61377, the average last spring frost (32°F) is April 26, based on NOAA 1991-2020 climate normals for the Minonk, IL weather station. There is a 1-in-10 chance of a frost after May 10.
- When is the first frost in Wenona, IL?
- The average first fall frost (32°F) is October 17. There is a 1-in-10 chance of frost by October 1, so tender plants are at risk from that point on.
- How long is the growing season in 61377?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 173 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.