Frost dates for Des Moines Intl Airport, IA
At Des Moines Intl Airport, the median last spring frost (32°F) is Apr 18 and the median first fall frost is Oct 20, for a typical growing season of 184 days. For a 90% chance that the last frost has passed, wait until May 2. Nearby ZIP codes are in USDA hardiness zone 5b.
- Apr 18Last spring frost (median)50% chance of 32°F after this date
- May 2Safer planting date10% chance of 32°F after this date
- Oct 20First fall frost (median)50% chance of 32°F by this date
- 184 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | Apr 15 | Apr 29 | May 10 |
| 32°F | Apr 4 | Apr 18 | May 2 |
| 28°F | Mar 25 | Apr 8 | Apr 22 |
| 24°F | Mar 12 | Mar 31 | Apr 13 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Sep 25 | Oct 9 | Oct 22 |
| 32°F | Oct 4 | Oct 20 | Nov 1 |
| 28°F | Oct 16 | Oct 30 | Nov 11 |
| 24°F | Oct 25 | Nov 6 | Nov 21 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 146 days | 163 days | 182 days |
| 32°F | 165 days | 184 days | 203 days |
| 28°F | 185 days | 203 days | 223 days |
| 24°F | 200 days | 220 days | 243 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 100% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 50321 | 5b | -15 to -10°F | 1 km |
| 50315 | 5b | -15 to -10°F | 3 km |
| 50312 | 5b | -15 to -10°F | 5 km |
| 50309 | 5b | -15 to -10°F | 6 km |
| 50320 | 5b | -15 to -10°F | 7 km |
| 50319 | 5b | -15 to -10°F | 8 km |
| 50311 | 5b | -15 to -10°F | 8 km |
| 50314 | 5b | -15 to -10°F | 8 km |
| 50265 | 5b | -15 to -10°F | 8 km |
| 50324 | 5b | -15 to -10°F | 9 km |
| 50316 | 5b | -15 to -10°F | 9 km |
| 50211 | 5b | -15 to -10°F | 10 km |
| 50310 | 5b | -15 to -10°F | 11 km |
| 50317 | 5b | -15 to -10°F | 13 km |
| 50061 | 5b | -15 to -10°F | 14 km |
| 50266 | 5b | -15 to -10°F | 14 km |
| 50327 | 5b | -15 to -10°F | 15 km |
| 50325 | 5b | -15 to -10°F | 15 km |
| 50047 | 5b | -15 to -10°F | 17 km |
| 50038 | 5b | -15 to -10°F | 21 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USW00014933, at 41.5339, -93.6531, elevation 292 m (957 ft).
- Data quality: Standard (24+ years of data), 26 years of freeze data.
- Average days per year at or below 32°F: 128.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Indianola 2w (19 km)
- Ankeny (22 km)
- Des Moines Wsfo-Johnston (23 km)
- Des Moines 17 E (31 km)
- Winterset 1s (39 km)
- Ames 5 SE (47 km)
- Perry (51 km)
- Ames Muni Airport (51 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.