Frost dates for 51011Chatsworth, IA
The average last spring frost in Chatsworth is May 1 and the average first fall frost is October 4, giving a typical growing season of about 155 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 1
- Average first fall frost
- Oct 4
- Growing season
- 155 days
Safer after May 14 (1-in-10 risk)
Possible by Sep 21 (1-in-10 risk)
Last frost typically in 179 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 27 · May 8 · May 24 | Sep 14 · Sep 26 · Oct 9 | 139 days | 100% |
| Frost / freeze (32°F) | Apr 17 · May 1 · May 14 | Sep 21 · Oct 4 · Oct 18 | 155 days | 100% |
| Hard freeze (28°F) | Apr 8 · Apr 22 · May 4 | Sep 30 · Oct 16 · Oct 29 | 174 days | 100% |
Planting calendar for Chatsworth
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 31 – Jun 6 |
| Tomatoes | Transplant outdoors | May 17 – Jun 14 |
| Peppers | Start seeds indoors | Mar 31 – May 1 |
| Peppers | Transplant outdoors | May 31 – Jul 1 |
| Eggplant | Start seeds indoors | Apr 17 – May 16 |
| Eggplant | Transplant outdoors | May 31 – Jul 1 |
| Cucumbers | Sow outdoors | May 31 – Jun 24 |
| Summer squash | Sow outdoors | May 17 – Jul 1 |
| Winter squash & pumpkins | Sow outdoors | May 31 – Jul 1 |
| Snap beans | Sow outdoors | May 17 – Jul 17 |
| Sweet corn | Sow outdoors | May 17 – Jun 14 |
| Watermelon & cantaloupe | Sow outdoors | May 31 – Jul 1 |
| Okra | Sow outdoors | May 24 – Jun 16 |
| Peas | Sow outdoors (spring) | Mar 31 – May 16 |
| Potatoes | Plant outdoors (spring) | Mar 31 – May 31 |
| Onions | Start seeds indoors (spring) | Feb 17 – Mar 16 |
| Onions | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (spring) | Mar 13 – Apr 16 |
| Broccoli | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (fall) | Jun 4 – Jun 14 |
| Broccoli | Transplant outdoors (fall) | Jul 4 – Jul 15 |
| Cabbage | Start seeds indoors (spring) | Mar 3 – Mar 31 |
| Cabbage | Transplant outdoors (spring) | Mar 31 – May 1 |
| Cabbage | Start seeds indoors (fall) | May 25 – Jun 24 |
| Cabbage | Transplant outdoors (fall) | Jun 24 – Jul 25 |
| Leaf lettuce | Sow outdoors (spring) | Mar 31 – Jun 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 24 – Aug 10 |
| Spinach | Sow outdoors (spring) | Mar 24 – May 7 |
| Spinach | Sow outdoors (fall) | Jul 11 – Aug 15 |
| Radishes | Sow outdoors (spring) | Mar 31 – May 21 |
| Radishes | Sow outdoors (fall) | Jun 24 – Aug 25 |
| Kale | Sow outdoors (spring) | Apr 17 – May 7 |
| Kale | Sow outdoors (fall) | Jun 17 – Jul 25 |
| Carrots | Sow outdoors (spring) | May 1 – Jun 16 |
| Carrots | Sow outdoors (fall) | May 25 – Jul 10 |
| Garlic | Plant outdoors (fall) | Sep 24 – Oct 25 |
Where these dates come from
ZIP code 51011 is matched to the NOAA station Hawarden, IA, 9.9 km away, at 1,190 ft elevation (29 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Hawarden, IA (used) | 1,190 ft | May 1 | Oct 4 |
| Sioux Ctr 2 Se, IA | 1,360 ft | Apr 30 | Oct 3 |
| Le Mars, IA | 1,195 ft | Apr 30 | Oct 4 |
| Centerville 6 Se, SD | 1,276 ft | May 2 | Oct 1 |
Frost dates near Chatsworth
- Akron, IA 51001 · last May 1, first Oct 4
- Hawarden, IA 51023 · last May 1, first Oct 4
- Alcester, SD 57001 · last May 1, first Oct 4
- Ireton, IA 51027 · last Apr 30, first Oct 3
- Hudson, SD 57034 · last May 1, first Oct 4
- Brunsville, IA 51008 · last Apr 30, first Oct 4
- Elk Point, SD 57025 · last May 3, first Oct 3
- Westfield, IA 51062 · last Apr 30, first Oct 4
Frequently asked questions
- When is the last frost in Chatsworth, IA?
- For ZIP code 51011, the average last spring frost (32°F) is May 1, based on NOAA 1991-2020 climate normals for the Hawarden, IA weather station. There is a 1-in-10 chance of a frost after May 14.
- When is the first frost in Chatsworth, IA?
- The average first fall frost (32°F) is October 4. There is a 1-in-10 chance of frost by September 21, so tender plants are at risk from that point on.
- How long is the growing season in 51011?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 155 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.