Frost dates for Lamoni, IA
At Lamoni, the median last spring frost (32°F) is Apr 16 and the median first fall frost is Oct 20, for a typical growing season of 187 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 16Last 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
- 187 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 13 | Apr 27 | May 11 |
| 32°F | Apr 2 | Apr 16 | May 2 |
| 28°F | Mar 19 | Apr 5 | Apr 19 |
| 24°F | Mar 9 | Mar 26 | Apr 12 |
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 27 | Oct 10 | Oct 23 |
| 32°F | Oct 6 | Oct 20 | Nov 1 |
| 28°F | Oct 16 | Oct 30 | Nov 11 |
| 24°F | Oct 23 | Nov 7 | Nov 22 |
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 | 165 days | 185 days |
| 32°F | 166 days | 187 days | 206 days |
| 28°F | 187 days | 207 days | 229 days |
| 24°F | 203 days | 226 days | 248 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 |
|---|---|---|---|
| 50140 | 5b | -15 to -10°F | 2 km |
| 64458 | 5b | -15 to -10°F | 19 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 USW00014993, at 40.6500, -94.0000, elevation 356 m (1,168 ft).
- Data quality: Estimated from nearby stations (2+ years), 2 years of freeze data.
- Average days per year at or below 32°F: 132.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Lamoni (6 km)
- Lamoni Muni Airport (8 km)
- Beaconsfield (18 km)
- Mount Ayr (21 km)
- Leon 6 ESE (31 km)
- Osceola (46 km)
- Allerton (53 km)
- Creston 2 SW (54 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.