Frost dates for 50595Webster City, IA
The average last spring frost in Webster City is May 3 and the average first fall frost is October 2, giving a typical growing season of about 150 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 3
- Average first fall frost
- Oct 2
- Growing season
- 150 days
Safer after May 16 (1-in-10 risk)
Possible by Sep 18 (1-in-10 risk)
Last frost typically in 188 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 30 · May 11 · May 24 | Sep 10 · Sep 23 · Oct 5 | 133 days | 100% |
| Frost / freeze (32°F) | Apr 20 · May 3 · May 16 | Sep 18 · Oct 2 · Oct 16 | 150 days | 100% |
| Hard freeze (28°F) | Apr 10 · Apr 24 · May 7 | Sep 27 · Oct 12 · Oct 25 | 169 days | 100% |
Planting calendar for Webster City
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 | Apr 2 – Jun 8 |
| Tomatoes | Transplant outdoors | May 19 – Jun 12 |
| Peppers | Start seeds indoors | Apr 2 – May 3 |
| Peppers | Transplant outdoors | Jun 2 – Jul 3 |
| Eggplant | Start seeds indoors | Apr 19 – May 18 |
| Eggplant | Transplant outdoors | Jun 2 – Jul 3 |
| Cucumbers | Sow outdoors | Jun 2 – Jun 22 |
| Summer squash | Sow outdoors | May 19 – Jul 3 |
| Winter squash & pumpkins | Sow outdoors | Jun 2 – Jul 3 |
| Snap beans | Sow outdoors | May 19 – Jul 15 |
| Sweet corn | Sow outdoors | May 19 – Jun 12 |
| Watermelon & cantaloupe | Sow outdoors | Jun 2 – Jul 3 |
| Okra | Sow outdoors | May 26 – Jun 18 |
| Peas | Sow outdoors (spring) | Apr 2 – May 18 |
| Potatoes | Plant outdoors (spring) | Apr 2 – Jun 2 |
| Onions | Start seeds indoors (spring) | Feb 19 – Mar 18 |
| Onions | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (spring) | Mar 15 – Apr 18 |
| Broccoli | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (fall) | Jun 2 – Jun 12 |
| Broccoli | Transplant outdoors (fall) | Jul 2 – Jul 13 |
| Cabbage | Start seeds indoors (spring) | Mar 5 – Apr 2 |
| Cabbage | Transplant outdoors (spring) | Apr 2 – May 3 |
| Cabbage | Start seeds indoors (fall) | May 23 – Jun 22 |
| Cabbage | Transplant outdoors (fall) | Jun 22 – Jul 23 |
| Leaf lettuce | Sow outdoors (spring) | Apr 2 – Jun 18 |
| Leaf lettuce | Sow outdoors (fall) | Jun 22 – Aug 8 |
| Spinach | Sow outdoors (spring) | Mar 26 – May 9 |
| Spinach | Sow outdoors (fall) | Jul 9 – Aug 13 |
| Radishes | Sow outdoors (spring) | Apr 2 – May 23 |
| Radishes | Sow outdoors (fall) | Jun 22 – Aug 23 |
| Kale | Sow outdoors (spring) | Apr 19 – May 9 |
| Kale | Sow outdoors (fall) | Jun 15 – Jul 23 |
| Carrots | Sow outdoors (spring) | May 3 – Jun 18 |
| Carrots | Sow outdoors (fall) | May 23 – Jul 8 |
| Garlic | Plant outdoors (fall) | Sep 22 – Oct 23 |
Where these dates come from
ZIP code 50595 is matched to the NOAA station Webster City, IA, 2.4 km away, at 1,072 ft elevation (6 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Webster City, IA (used) | 1,072 ft | May 3 | Oct 2 |
| Clarion, IA | 1,156 ft | Apr 30 | Oct 10 |
| Ft Dodge 5Nnw, IA | 1,115 ft | Apr 28 | Oct 8 |
| Dakota City, IA | 1,110 ft | Apr 26 | Oct 12 |
Frost dates near Webster City
- Kamrar, IA 50132 · last May 3, first Oct 2
- Woolstock, IA 50599 · last May 3, first Oct 2
- Blairsburg, IA 50034 · last May 3, first Oct 2
- Duncombe, IA 50532 · last Apr 28, first Oct 8
- Stanhope, IA 50246 · last May 3, first Oct 2
- Vincent, IA 50594 · last Apr 28, first Oct 8
- Stratford, IA 50249 · last May 3, first Oct 2
- Lehigh, IA 50557 · last May 3, first Oct 2
Frequently asked questions
- When is the last frost in Webster City, IA?
- For ZIP code 50595, the average last spring frost (32°F) is May 3, based on NOAA 1991-2020 climate normals for the Webster City, IA weather station. There is a 1-in-10 chance of a frost after May 16.
- When is the first frost in Webster City, IA?
- The average first fall frost (32°F) is October 2. There is a 1-in-10 chance of frost by September 18, so tender plants are at risk from that point on.
- How long is the growing season in 50595?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 150 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.