Frost dates for 62942Grand Tower, IL
The average last spring frost in Grand Tower is April 9 and the average first fall frost is October 22, giving a typical growing season of about 195 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 9
- Average first fall frost
- Oct 22
- Growing season
- 195 days
Safer after Apr 25 (1-in-10 risk)
Possible by Oct 8 (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 6 · Apr 21 · May 6 | Sep 30 · Oct 12 · Oct 23 | 173 days | 100% |
| Frost / freeze (32°F) | Mar 24 · Apr 9 · Apr 25 | Oct 8 · Oct 22 · Nov 1 | 195 days | 100% |
| Hard freeze (28°F) | Mar 11 · Mar 30 · Apr 14 | Oct 21 · Nov 1 · Nov 17 | 217 days | 100% |
Planting calendar for Grand Tower
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 9 – May 15 |
| Tomatoes | Transplant outdoors | Apr 25 – Jul 2 |
| Peppers | Start seeds indoors | Mar 9 – Apr 9 |
| Peppers | Transplant outdoors | May 9 – Jun 9 |
| Eggplant | Start seeds indoors | Mar 26 – Apr 24 |
| Eggplant | Transplant outdoors | May 9 – Jun 9 |
| Cucumbers | Sow outdoors | May 9 – Jul 12 |
| Summer squash | Sow outdoors | Apr 25 – Jun 9 |
| Winter squash & pumpkins | Sow outdoors | May 9 – Jun 9 |
| Snap beans | Sow outdoors | Apr 25 – Aug 4 |
| Sweet corn | Sow outdoors | Apr 25 – Jul 2 |
| Watermelon & cantaloupe | Sow outdoors | May 9 – Jun 9 |
| Okra | Sow outdoors | May 2 – May 25 |
| Peas | Sow outdoors (spring) | Mar 9 – Apr 24 |
| Potatoes | Plant outdoors (spring) | Mar 9 – May 9 |
| Onions | Start seeds indoors (spring) | Jan 26 – Feb 22 |
| Onions | Transplant outdoors (spring) | Mar 26 – Apr 24 |
| Broccoli | Start seeds indoors (spring) | Feb 19 – Mar 25 |
| Broccoli | Transplant outdoors (spring) | Mar 26 – Apr 24 |
| Broccoli | Start seeds indoors (fall) | Jun 22 – Jul 2 |
| Broccoli | Transplant outdoors (fall) | Jul 22 – Aug 2 |
| Cabbage | Start seeds indoors (spring) | Feb 9 – Mar 9 |
| Cabbage | Transplant outdoors (spring) | Mar 9 – Apr 9 |
| Cabbage | Start seeds indoors (fall) | Jun 12 – Jul 12 |
| Cabbage | Transplant outdoors (fall) | Jul 12 – Aug 12 |
| Leaf lettuce | Sow outdoors (spring) | Mar 9 – May 25 |
| Leaf lettuce | Sow outdoors (fall) | Jul 12 – Aug 28 |
| Spinach | Sow outdoors (spring) | Mar 2 – Apr 15 |
| Spinach | Sow outdoors (fall) | Jul 29 – Sep 2 |
| Radishes | Sow outdoors (spring) | Mar 9 – Apr 29 |
| Radishes | Sow outdoors (fall) | Jul 12 – Sep 12 |
| Kale | Sow outdoors (spring) | Mar 26 – Apr 15 |
| Kale | Sow outdoors (fall) | Jul 5 – Aug 12 |
| Carrots | Sow outdoors (spring) | Apr 9 – May 25 |
| Carrots | Sow outdoors (fall) | Jun 12 – Jul 28 |
| Garlic | Plant outdoors (fall) | Oct 12 – Nov 12 |
Where these dates come from
ZIP code 62942 is matched to the NOAA station Carbondale Southern Il Ap, IL, 27.4 km away, at 406 ft elevation (34 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Carbondale Southern Il Ap, IL (used) | 406 ft | Apr 9 | Oct 22 |
| Anna 2 Nne, IL | 640 ft | Apr 8 | Oct 29 |
| Carbondale Sewage Plt, IL | 390 ft | Apr 9 | Oct 22 |
| Jackson, MO | 440 ft | Apr 7 | Oct 29 |
Frost dates near Grand Tower
- Altenburg, MO 63732 · last Apr 7, first Oct 29
- Pomona, IL 62975 · last Apr 9, first Oct 22
- Jacob, IL 62950 · last Apr 9, first Oct 22
- Gorham, IL 62940 · last Apr 9, first Oct 22
- Brazeau, MO 63737 · last Apr 19, first Oct 20
- Wolf Lake, IL 62998 · last Apr 7, first Oct 29
- Frohna, MO 63748 · last Apr 19, first Oct 20
- Uniontown, MO 63783 · last Apr 7, first Oct 29
Frequently asked questions
- When is the last frost in Grand Tower, IL?
- For ZIP code 62942, the average last spring frost (32°F) is April 9, based on NOAA 1991-2020 climate normals for the Carbondale Southern Il Ap, IL weather station. There is a 1-in-10 chance of a frost after April 25.
- When is the first frost in Grand Tower, IL?
- The average first fall frost (32°F) is October 22. There is a 1-in-10 chance of frost by October 8, so tender plants are at risk from that point on.
- How long is the growing season in 62942?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 195 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.