Frost dates for 61875Seymour, IL
The average last spring frost in Seymour is April 23 and the average first fall frost is October 13, giving a typical growing season of about 170 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 23
- Average first fall frost
- Oct 13
- Growing season
- 170 days
Safer after May 9 (1-in-10 risk)
Possible by Sep 28 (1-in-10 risk)
Last frost typically in 174 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 20 · May 4 · May 22 | Sep 20 · Oct 3 · Oct 16 | 151 days | 100% |
| Frost / freeze (32°F) | Apr 9 · Apr 23 · May 9 | Sep 28 · Oct 13 · Oct 25 | 170 days | 100% |
| Hard freeze (28°F) | Mar 29 · Apr 11 · Apr 28 | Oct 8 · Oct 23 · Nov 4 | 193 days | 100% |
Planting calendar for Seymour
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 23 – May 29 |
| Tomatoes | Transplant outdoors | May 9 – Jun 23 |
| Peppers | Start seeds indoors | Mar 23 – Apr 23 |
| Peppers | Transplant outdoors | May 23 – Jun 23 |
| Eggplant | Start seeds indoors | Apr 9 – May 8 |
| Eggplant | Transplant outdoors | May 23 – Jun 23 |
| Cucumbers | Sow outdoors | May 23 – Jul 3 |
| Summer squash | Sow outdoors | May 9 – Jun 23 |
| Winter squash & pumpkins | Sow outdoors | May 23 – Jun 23 |
| Snap beans | Sow outdoors | May 9 – Jul 26 |
| Sweet corn | Sow outdoors | May 9 – Jun 23 |
| Watermelon & cantaloupe | Sow outdoors | May 23 – Jun 23 |
| Okra | Sow outdoors | May 16 – Jun 8 |
| Peas | Sow outdoors (spring) | Mar 23 – May 8 |
| Potatoes | Plant outdoors (spring) | Mar 23 – May 23 |
| Onions | Start seeds indoors (spring) | Feb 9 – Mar 8 |
| Onions | Transplant outdoors (spring) | Apr 9 – May 8 |
| Broccoli | Start seeds indoors (spring) | Mar 5 – Apr 8 |
| Broccoli | Transplant outdoors (spring) | Apr 9 – May 8 |
| Broccoli | Start seeds indoors (fall) | Jun 13 – Jun 23 |
| Broccoli | Transplant outdoors (fall) | Jul 13 – Jul 24 |
| Cabbage | Start seeds indoors (spring) | Feb 23 – Mar 23 |
| Cabbage | Transplant outdoors (spring) | Mar 23 – Apr 23 |
| Cabbage | Start seeds indoors (fall) | Jun 3 – Jul 3 |
| Cabbage | Transplant outdoors (fall) | Jul 3 – Aug 3 |
| Leaf lettuce | Sow outdoors (spring) | Mar 23 – Jun 8 |
| Leaf lettuce | Sow outdoors (fall) | Jul 3 – Aug 19 |
| Spinach | Sow outdoors (spring) | Mar 16 – Apr 29 |
| Spinach | Sow outdoors (fall) | Jul 20 – Aug 24 |
| Radishes | Sow outdoors (spring) | Mar 23 – May 13 |
| Radishes | Sow outdoors (fall) | Jul 3 – Sep 3 |
| Kale | Sow outdoors (spring) | Apr 9 – Apr 29 |
| Kale | Sow outdoors (fall) | Jun 26 – Aug 3 |
| Carrots | Sow outdoors (spring) | Apr 23 – Jun 8 |
| Carrots | Sow outdoors (fall) | Jun 3 – Jul 19 |
| Garlic | Plant outdoors (fall) | Oct 3 – Nov 3 |
Where these dates come from
ZIP code 61875 is matched to the NOAA station Champaign 9 Sw, IL, 7.6 km away, at 700 ft elevation (2 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Champaign 9 Sw, IL (used) | 700 ft | Apr 23 | Oct 13 |
| Champaign Willard Ap, IL | 754 ft | Apr 19 | Oct 17 |
| Champaign 3S, IL | 721 ft | Apr 15 | Oct 24 |
| Rantoul, IL | 740 ft | Apr 21 | Oct 18 |
Frost dates near Seymour
- Bondville, IL 61815 · last Apr 23, first Oct 13
- Champaign, IL 61826 · last Apr 23, first Oct 13
- White Heath, IL 61884 · last Apr 23, first Oct 13
- Mahomet, IL 61853 · last Apr 23, first Oct 13
- Mansfield, IL 61854 · last Apr 23, first Oct 13
- Monticello, IL 61856 · last Apr 23, first Oct 13
- Savoy, IL 61874 · last Apr 15, first Oct 24
- Urbana, IL 61803 · last Apr 15, first Oct 24
Frequently asked questions
- When is the last frost in Seymour, IL?
- For ZIP code 61875, the average last spring frost (32°F) is April 23, based on NOAA 1991-2020 climate normals for the Champaign 9 Sw, IL weather station. There is a 1-in-10 chance of a frost after May 9.
- When is the first frost in Seymour, IL?
- The average first fall frost (32°F) is October 13. There is a 1-in-10 chance of frost by September 28, so tender plants are at risk from that point on.
- How long is the growing season in 61875?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 170 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.