Frost dates for 61437Gladstone, IL
The average last spring frost in Gladstone is April 8 and the average first fall frost is October 29, 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 29
- Growing season
- 202 days
Safer after Apr 23 (1-in-10 risk)
Possible by Oct 17 (1-in-10 risk)
Last frost typically in 160 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 20 · May 5 | Oct 4 · Oct 19 · Oct 31 | 181 days | 100% |
| Frost / freeze (32°F) | Mar 26 · Apr 8 · Apr 23 | Oct 17 · Oct 29 · Nov 10 | 202 days | 100% |
| Hard freeze (28°F) | Mar 14 · Mar 31 · Apr 13 | Oct 27 · Nov 7 · Nov 21 | 222 days | 100% |
Planting calendar for Gladstone
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 9 |
| 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 19 |
| Summer squash | Sow outdoors | Apr 24 – Jun 8 |
| Winter squash & pumpkins | Sow outdoors | May 8 – Jun 8 |
| Snap beans | Sow outdoors | Apr 24 – Aug 11 |
| Sweet corn | Sow outdoors | Apr 24 – Jul 9 |
| 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 29 – Jul 9 |
| Broccoli | Transplant outdoors (fall) | Jul 29 – Aug 9 |
| Cabbage | Start seeds indoors (spring) | Feb 8 – Mar 8 |
| Cabbage | Transplant outdoors (spring) | Mar 8 – Apr 8 |
| Cabbage | Start seeds indoors (fall) | Jun 19 – Jul 19 |
| Cabbage | Transplant outdoors (fall) | Jul 19 – Aug 19 |
| Leaf lettuce | Sow outdoors (spring) | Mar 8 – May 24 |
| Leaf lettuce | Sow outdoors (fall) | Jul 19 – Sep 4 |
| Spinach | Sow outdoors (spring) | Mar 1 – Apr 14 |
| Spinach | Sow outdoors (fall) | Aug 5 – Sep 9 |
| Radishes | Sow outdoors (spring) | Mar 8 – Apr 28 |
| Radishes | Sow outdoors (fall) | Jul 19 – Sep 19 |
| Kale | Sow outdoors (spring) | Mar 25 – Apr 14 |
| Kale | Sow outdoors (fall) | Jul 12 – Aug 19 |
| Carrots | Sow outdoors (spring) | Apr 8 – May 24 |
| Carrots | Sow outdoors (fall) | Jun 19 – Aug 4 |
| Garlic | Plant outdoors (fall) | Oct 19 – Nov 19 |
Where these dates come from
ZIP code 61437 is matched to the NOAA station Gladstone Dam 18, IL, 5.5 km away, at 538 ft elevation (7 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Gladstone Dam 18, IL (used) | 538 ft | Apr 8 | Oct 29 |
| Burlington 2S, IA | 690 ft | Apr 18 | Oct 20 |
| Burlington Muni Ap, IA | 692 ft | Apr 15 | Oct 20 |
| Monmouth 4Nw, IL | 724 ft | Apr 22 | Oct 14 |
Frost dates near Gladstone
- Carman, IL 61425 · last Apr 18, first Oct 20
- Burlington, IA 52601 · last Apr 15, first Oct 20
- Stronghurst, IL 61480 · last Apr 18, first Oct 20
- Biggsville, IL 61418 · last Apr 22, first Oct 14
- Oquawka, IL 61469 · last Apr 8, first Oct 29
- Media, IL 61460 · last Apr 18, first Oct 20
- West Burlington, IA 52655 · last Apr 15, first Oct 20
- Lomax, IL 61454 · last Apr 21, first Oct 19
Frequently asked questions
- When is the last frost in Gladstone, IL?
- For ZIP code 61437, the average last spring frost (32°F) is April 8, based on NOAA 1991-2020 climate normals for the Gladstone Dam 18, IL weather station. There is a 1-in-10 chance of a frost after April 23.
- When is the first frost in Gladstone, IL?
- The average first fall frost (32°F) is October 29. There is a 1-in-10 chance of frost by October 17, so tender plants are at risk from that point on.
- How long is the growing season in 61437?
- 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.