Frost dates for 62261Modoc, IL
The average last spring frost in Modoc is April 8 and the average first fall frost is October 30, giving a typical growing season of about 202 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 8
- Average first fall frost
- Oct 30
- Growing season
- 202 days
Safer after Apr 25 (1-in-10 risk)
Possible by Oct 15 (1-in-10 risk)
Last frost typically in 159 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 5 · Apr 20 · May 5 | Oct 4 · Oct 18 · Oct 31 | 179 days | 100% |
| Frost / freeze (32°F) | Mar 22 · Apr 8 · Apr 25 | Oct 15 · Oct 30 · Nov 13 | 202 days | 100% |
| Hard freeze (28°F) | Mar 9 · Mar 28 · Apr 13 | Oct 27 · Nov 10 · Nov 30 | 228 days | 100% |
Planting calendar for Modoc
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 8 – May 14 |
| Tomatoes | Transplant outdoors | Apr 24 – Jul 10 |
| Peppers | Start seeds indoors | Mar 8 – Apr 8 |
| Peppers | Transplant outdoors | May 8 – Jun 8 |
| Eggplant | Start seeds indoors | Mar 25 – Apr 23 |
| Eggplant | Transplant outdoors | May 8 – Jun 8 |
| Cucumbers | Sow outdoors | May 8 – Jul 20 |
| Summer squash | Sow outdoors | Apr 24 – Jun 8 |
| Winter squash & pumpkins | Sow outdoors | May 8 – Jun 8 |
| Snap beans | Sow outdoors | Apr 24 – Aug 12 |
| Sweet corn | Sow outdoors | Apr 24 – Jul 10 |
| Watermelon & cantaloupe | Sow outdoors | May 8 – Jun 8 |
| Okra | Sow outdoors | May 1 – May 24 |
| Peas | Sow outdoors (spring) | Mar 8 – Apr 23 |
| Potatoes | Plant outdoors (spring) | Mar 8 – May 8 |
| Onions | Start seeds indoors (spring) | Jan 25 – Feb 21 |
| Onions | Transplant outdoors (spring) | Mar 25 – Apr 23 |
| Broccoli | Start seeds indoors (spring) | Feb 18 – Mar 24 |
| Broccoli | Transplant outdoors (spring) | Mar 25 – Apr 23 |
| Broccoli | Start seeds indoors (fall) | Jun 30 – Jul 10 |
| Broccoli | Transplant outdoors (fall) | Jul 30 – Aug 10 |
| Cabbage | Start seeds indoors (spring) | Feb 8 – Mar 8 |
| Cabbage | Transplant outdoors (spring) | Mar 8 – Apr 8 |
| Cabbage | Start seeds indoors (fall) | Jun 20 – Jul 20 |
| Cabbage | Transplant outdoors (fall) | Jul 20 – Aug 20 |
| Leaf lettuce | Sow outdoors (spring) | Mar 8 – May 24 |
| Leaf lettuce | Sow outdoors (fall) | Jul 20 – Sep 5 |
| Spinach | Sow outdoors (spring) | Mar 1 – Apr 14 |
| Spinach | Sow outdoors (fall) | Aug 6 – Sep 10 |
| Radishes | Sow outdoors (spring) | Mar 8 – Apr 28 |
| Radishes | Sow outdoors (fall) | Jul 20 – Sep 20 |
| Kale | Sow outdoors (spring) | Mar 25 – Apr 14 |
| Kale | Sow outdoors (fall) | Jul 13 – Aug 20 |
| Carrots | Sow outdoors (spring) | Apr 8 – May 24 |
| Carrots | Sow outdoors (fall) | Jun 20 – Aug 5 |
| Garlic | Plant outdoors (fall) | Oct 20 – Nov 20 |
Where these dates come from
ZIP code 62261 is matched to the NOAA station Kaskaskia Rvr Navigation Lock, IL, 9.7 km away, at 380 ft elevation (115 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Kaskaskia Rvr Navigation Lock, IL (used) | 380 ft | Apr 8 | Oct 30 |
| Sparta 1 W, IL | 535 ft | Apr 12 | Oct 22 |
| Perryville Wtp, MO | 502 ft | Apr 19 | Oct 20 |
| Festus, MO | 600 ft | Apr 9 | Oct 26 |
Frost dates near Modoc
- Prairie Du Rocher, IL 62277 · last Apr 8, first Oct 30
- Evansville, IL 62242 · last Apr 8, first Oct 30
- Ellis Grove, IL 62241 · last Apr 8, first Oct 30
- Renault, IL 62279 · last Apr 9, first Oct 26
- Red Bud, IL 62278 · last Apr 8, first Oct 30
- Walsh, IL 62297 · last Apr 12, first Oct 22
- Baldwin, IL 62217 · last Apr 12, first Oct 22
- Fults, IL 62244 · last Apr 9, first Oct 26
Frequently asked questions
- When is the last frost in Modoc, IL?
- For ZIP code 62261, the average last spring frost (32°F) is April 8, based on NOAA 1991-2020 climate normals for the Kaskaskia Rvr Navigation Lock, IL weather station. There is a 1-in-10 chance of a frost after April 25.
- When is the first frost in Modoc, IL?
- The average first fall frost (32°F) is October 30. There is a 1-in-10 chance of frost by October 15, so tender plants are at risk from that point on.
- How long is the growing season in 62261?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 202 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.