Frost dates for 61817Catlin, IL
The average last spring frost in Catlin is April 21 and the average first fall frost is October 20, giving a typical growing season of about 181 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 21
- Average first fall frost
- Oct 20
- Growing season
- 181 days
Safer after May 7 (1-in-10 risk)
Possible by Oct 6 (1-in-10 risk)
Last frost typically in 173 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 18 · May 3 · May 19 | Sep 28 · Oct 10 · Oct 22 | 160 days | 100% |
| Frost / freeze (32°F) | Apr 6 · Apr 21 · May 7 | Oct 6 · Oct 20 · Nov 1 | 181 days | 100% |
| Hard freeze (28°F) | Mar 25 · Apr 8 · Apr 24 | Oct 17 · Oct 31 · Nov 13 | 205 days | 100% |
Planting calendar for Catlin
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 21 – May 27 |
| Tomatoes | Transplant outdoors | May 7 – Jun 30 |
| Peppers | Start seeds indoors | Mar 21 – Apr 21 |
| Peppers | Transplant outdoors | May 21 – Jun 21 |
| Eggplant | Start seeds indoors | Apr 7 – May 6 |
| Eggplant | Transplant outdoors | May 21 – Jun 21 |
| Cucumbers | Sow outdoors | May 21 – Jul 10 |
| Summer squash | Sow outdoors | May 7 – Jun 21 |
| Winter squash & pumpkins | Sow outdoors | May 21 – Jun 21 |
| Snap beans | Sow outdoors | May 7 – Aug 2 |
| Sweet corn | Sow outdoors | May 7 – Jun 30 |
| Watermelon & cantaloupe | Sow outdoors | May 21 – Jun 21 |
| Okra | Sow outdoors | May 14 – Jun 6 |
| Peas | Sow outdoors (spring) | Mar 21 – May 6 |
| Potatoes | Plant outdoors (spring) | Mar 21 – May 21 |
| Onions | Start seeds indoors (spring) | Feb 7 – Mar 6 |
| Onions | Transplant outdoors (spring) | Apr 7 – May 6 |
| Broccoli | Start seeds indoors (spring) | Mar 3 – Apr 6 |
| Broccoli | Transplant outdoors (spring) | Apr 7 – May 6 |
| Broccoli | Start seeds indoors (fall) | Jun 20 – Jun 30 |
| Broccoli | Transplant outdoors (fall) | Jul 20 – Jul 31 |
| Cabbage | Start seeds indoors (spring) | Feb 21 – Mar 21 |
| Cabbage | Transplant outdoors (spring) | Mar 21 – Apr 21 |
| Cabbage | Start seeds indoors (fall) | Jun 10 – Jul 10 |
| Cabbage | Transplant outdoors (fall) | Jul 10 – Aug 10 |
| Leaf lettuce | Sow outdoors (spring) | Mar 21 – Jun 6 |
| Leaf lettuce | Sow outdoors (fall) | Jul 10 – Aug 26 |
| Spinach | Sow outdoors (spring) | Mar 14 – Apr 27 |
| Spinach | Sow outdoors (fall) | Jul 27 – Aug 31 |
| Radishes | Sow outdoors (spring) | Mar 21 – May 11 |
| Radishes | Sow outdoors (fall) | Jul 10 – Sep 10 |
| Kale | Sow outdoors (spring) | Apr 7 – Apr 27 |
| Kale | Sow outdoors (fall) | Jul 3 – Aug 10 |
| Carrots | Sow outdoors (spring) | Apr 21 – Jun 6 |
| Carrots | Sow outdoors (fall) | Jun 10 – Jul 26 |
| Garlic | Plant outdoors (fall) | Oct 10 – Nov 10 |
Where these dates come from
ZIP code 61817 is matched to the NOAA station Danville, IL, 9.4 km away, at 555 ft elevation (101 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Danville, IL (used) | 555 ft | Apr 21 | Oct 20 |
| Sidell 4N, IL | 672 ft | Apr 19 | Oct 19 |
| Perrysville 4 Wnw, IN | 611 ft | Apr 23 | Oct 14 |
| Ogden, IL | 675 ft | Apr 20 | Oct 21 |
Frost dates near Catlin
- Tilton, IL 61833 · last Apr 21, first Oct 20
- Westville, IL 61883 · last Apr 23, first Oct 14
- Oakwood, IL 61858 · last Apr 21, first Oct 20
- Danville, IL 61834 · last Apr 21, first Oct 20
- Fairmount, IL 61841 · last Apr 19, first Oct 19
- Georgetown, IL 61846 · last Apr 19, first Oct 19
- Muncie, IL 61857 · last Apr 19, first Oct 19
- Fithian, IL 61844 · last Apr 19, first Oct 19
Frequently asked questions
- When is the last frost in Catlin, IL?
- For ZIP code 61817, the average last spring frost (32°F) is April 21, based on NOAA 1991-2020 climate normals for the Danville, IL weather station. There is a 1-in-10 chance of a frost after May 7.
- When is the first frost in Catlin, IL?
- The average first fall frost (32°F) is October 20. There is a 1-in-10 chance of frost by October 6, so tender plants are at risk from that point on.
- How long is the growing season in 61817?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 181 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.