Frost dates for 50144Leon, IA
The average last spring frost in Leon is April 30 and the average first fall frost is October 8, giving a typical growing season of about 161 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- Apr 30
- Average first fall frost
- Oct 8
- Growing season
- 161 days
Safer after May 15 (1-in-10 risk)
Possible by Sep 26 (1-in-10 risk)
Last frost typically in 185 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 24 · May 9 · May 24 | Sep 17 · Sep 29 · Oct 12 | 143 days | 100% |
| Frost / freeze (32°F) | Apr 16 · Apr 30 · May 15 | Sep 26 · Oct 8 · Oct 22 | 161 days | 100% |
| Hard freeze (28°F) | Apr 3 · Apr 19 · May 4 | Oct 4 · Oct 19 · Nov 1 | 183 days | 100% |
Planting calendar for Leon
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 30 – Jun 5 |
| Tomatoes | Transplant outdoors | May 16 – Jun 18 |
| Peppers | Start seeds indoors | Mar 30 – Apr 30 |
| Peppers | Transplant outdoors | May 30 – Jun 30 |
| Eggplant | Start seeds indoors | Apr 16 – May 15 |
| Eggplant | Transplant outdoors | May 30 – Jun 30 |
| Cucumbers | Sow outdoors | May 30 – Jun 28 |
| Summer squash | Sow outdoors | May 16 – Jun 30 |
| Winter squash & pumpkins | Sow outdoors | May 30 – Jun 30 |
| Snap beans | Sow outdoors | May 16 – Jul 21 |
| Sweet corn | Sow outdoors | May 16 – Jun 18 |
| Watermelon & cantaloupe | Sow outdoors | May 30 – Jun 30 |
| Okra | Sow outdoors | May 23 – Jun 15 |
| Peas | Sow outdoors (spring) | Mar 30 – May 15 |
| Potatoes | Plant outdoors (spring) | Mar 30 – May 30 |
| Onions | Start seeds indoors (spring) | Feb 16 – Mar 15 |
| Onions | Transplant outdoors (spring) | Apr 16 – May 15 |
| Broccoli | Start seeds indoors (spring) | Mar 12 – Apr 15 |
| Broccoli | Transplant outdoors (spring) | Apr 16 – May 15 |
| Broccoli | Start seeds indoors (fall) | Jun 8 – Jun 18 |
| Broccoli | Transplant outdoors (fall) | Jul 8 – Jul 19 |
| Cabbage | Start seeds indoors (spring) | Mar 2 – Mar 30 |
| Cabbage | Transplant outdoors (spring) | Mar 30 – Apr 30 |
| Cabbage | Start seeds indoors (fall) | May 29 – Jun 28 |
| Cabbage | Transplant outdoors (fall) | Jun 28 – Jul 29 |
| Leaf lettuce | Sow outdoors (spring) | Mar 30 – Jun 15 |
| Leaf lettuce | Sow outdoors (fall) | Jun 28 – Aug 14 |
| Spinach | Sow outdoors (spring) | Mar 23 – May 6 |
| Spinach | Sow outdoors (fall) | Jul 15 – Aug 19 |
| Radishes | Sow outdoors (spring) | Mar 30 – May 20 |
| Radishes | Sow outdoors (fall) | Jun 28 – Aug 29 |
| Kale | Sow outdoors (spring) | Apr 16 – May 6 |
| Kale | Sow outdoors (fall) | Jun 21 – Jul 29 |
| Carrots | Sow outdoors (spring) | Apr 30 – Jun 15 |
| Carrots | Sow outdoors (fall) | May 29 – Jul 14 |
| Garlic | Plant outdoors (fall) | Sep 28 – Oct 29 |
Where these dates come from
ZIP code 50144 is matched to the NOAA station Leon 6 Ese, IA, 8.3 km away, at 1,000 ft elevation (102 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Leon 6 Ese, IA (used) | 1,000 ft | Apr 30 | Oct 8 |
| Lamoni Muni Ap, IA | 1,131 ft | Apr 16 | Oct 21 |
| Lamoni, IA | 1,128 ft | Apr 17 | Oct 21 |
| Lamoni, IA | 1,168 ft | Apr 16 | Oct 20 |
Frost dates near Leon
- Decatur, IA 50067 · last Apr 16, first Oct 21
- Garden Grove, IA 50103 · last Apr 30, first Oct 8
- Davis City, IA 50065 · last Apr 16, first Oct 21
- Van Wert, IA 50262 · last Apr 29, first Oct 9
- Weldon, IA 50264 · last Apr 29, first Oct 9
- Grand River, IA 50108 · last Apr 23, first Oct 17
- Lamoni, IA 50140 · last Apr 17, first Oct 21
- Humeston, IA 50123 · last Apr 21, first Oct 19
Frequently asked questions
- When is the last frost in Leon, IA?
- For ZIP code 50144, the average last spring frost (32°F) is April 30, based on NOAA 1991-2020 climate normals for the Leon 6 Ese, IA weather station. There is a 1-in-10 chance of a frost after May 15.
- When is the first frost in Leon, IA?
- The average first fall frost (32°F) is October 8. There is a 1-in-10 chance of frost by September 26, so tender plants are at risk from that point on.
- How long is the growing season in 50144?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 161 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.