Frost dates for 51331Arnolds Park, IA
The average last spring frost in Arnolds Park is May 1 and the average first fall frost is October 6, giving a typical growing season of about 158 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 1
- Average first fall frost
- Oct 6
- Growing season
- 158 days
Safer after May 14 (1-in-10 risk)
Possible by Sep 24 (1-in-10 risk)
Last frost typically in 186 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 28 · May 9 · May 22 | Sep 15 · Sep 28 · Oct 11 | 141 days | 100% |
| Frost / freeze (32°F) | Apr 17 · May 1 · May 14 | Sep 24 · Oct 6 · Oct 21 | 158 days | 100% |
| Hard freeze (28°F) | Apr 6 · Apr 21 · May 4 | Oct 2 · Oct 17 · Oct 29 | 178 days | 100% |
Planting calendar for Arnolds Park
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 16 |
| 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 26 |
| Summer squash | Sow outdoors | May 17 – Jul 1 |
| Winter squash & pumpkins | Sow outdoors | May 31 – Jul 1 |
| Snap beans | Sow outdoors | May 17 – Jul 19 |
| Sweet corn | Sow outdoors | May 17 – Jun 16 |
| 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 6 – Jun 16 |
| Broccoli | Transplant outdoors (fall) | Jul 6 – Jul 17 |
| Cabbage | Start seeds indoors (spring) | Mar 3 – Mar 31 |
| Cabbage | Transplant outdoors (spring) | Mar 31 – May 1 |
| Cabbage | Start seeds indoors (fall) | May 27 – Jun 26 |
| Cabbage | Transplant outdoors (fall) | Jun 26 – Jul 27 |
| Leaf lettuce | Sow outdoors (spring) | Mar 31 – Jun 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 26 – Aug 12 |
| Spinach | Sow outdoors (spring) | Mar 24 – May 7 |
| Spinach | Sow outdoors (fall) | Jul 13 – Aug 17 |
| Radishes | Sow outdoors (spring) | Mar 31 – May 21 |
| Radishes | Sow outdoors (fall) | Jun 26 – Aug 27 |
| Kale | Sow outdoors (spring) | Apr 17 – May 7 |
| Kale | Sow outdoors (fall) | Jun 19 – Jul 27 |
| Carrots | Sow outdoors (spring) | May 1 – Jun 16 |
| Carrots | Sow outdoors (fall) | May 27 – Jul 12 |
| Garlic | Plant outdoors (fall) | Sep 26 – Oct 27 |
Where these dates come from
ZIP code 51331 is matched to the NOAA station Milford 4 Nw, IA, 5 km away, at 1,402 ft elevation (4 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Milford 4 Nw, IA (used) | 1,402 ft | May 1 | Oct 6 |
| Spirit Lake, IA | 1,420 ft | Apr 28 | Oct 11 |
| Lake Park, IA | 1,465 ft | Apr 30 | Oct 10 |
| Spencer 1 N, IA | 1,326 ft | May 1 | Oct 3 |
Frost dates near Arnolds Park
- Okoboji, IA 51355 · last Apr 28, first Oct 11
- Milford, IA 51351 · last May 1, first Oct 6
- Spirit Lake, IA 51360 · last Apr 28, first Oct 11
- Terril, IA 51364 · last Apr 28, first Oct 11
- Superior, IA 51363 · last Apr 28, first Oct 11
- Lake Park, IA 51347 · last Apr 30, first Oct 10
- Spencer, IA 51301 · last May 1, first Oct 3
- Estherville, IA 51334 · last May 2, first Sep 30
Frequently asked questions
- When is the last frost in Arnolds Park, IA?
- For ZIP code 51331, the average last spring frost (32°F) is May 1, based on NOAA 1991-2020 climate normals for the Milford 4 Nw, IA weather station. There is a 1-in-10 chance of a frost after May 14.
- When is the first frost in Arnolds Park, IA?
- The average first fall frost (32°F) is October 6. There is a 1-in-10 chance of frost by September 24, so tender plants are at risk from that point on.
- How long is the growing season in 51331?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 158 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.