Frost dates for Anamosa 3 SSW, IA
At Anamosa 3 SSW, the median last spring frost (32°F) is Apr 27 and the median first fall frost is Oct 13, for a typical growing season of 170 days. For a 90% chance that the last frost has passed, wait until May 10. Nearby ZIP codes are in USDA hardiness zone 5a.
- Apr 27Last spring frost (median)50% chance of 32°F after this date
- May 10Safer planting date10% chance of 32°F after this date
- Oct 13First fall frost (median)50% chance of 32°F by this date
- 170 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 23 | May 7 | May 19 |
| 32°F | Apr 12 | Apr 27 | May 10 |
| 28°F | Apr 1 | Apr 14 | May 1 |
| 24°F | Mar 16 | Apr 3 | Apr 19 |
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 21 | Oct 4 | Oct 15 |
| 32°F | Sep 30 | Oct 13 | Oct 25 |
| 28°F | Oct 10 | Oct 24 | Nov 5 |
| 24°F | Oct 21 | Nov 2 | Nov 17 |
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 | 132 days | 150 days | 167 days |
| 32°F | 151 days | 170 days | 189 days |
| 28°F | 172 days | 192 days | 211 days |
| 24°F | 194 days | 213 days | 235 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 |
|---|---|---|---|
| 52305 | 5a | -20 to -15°F | 7 km |
| 52336 | 5a | -20 to -15°F | 11 km |
| 52320 | 5a | -20 to -15°F | 15 km |
| 52253 | 5a | -20 to -15°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 USC00130214, at 42.0772, -91.3028, elevation 276 m (906 ft).
- Data quality: Estimated from nearby stations (2+ years), 9 years of freeze data.
- Average days per year at or below 32°F: 148.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Anamosa 1 WNW (4 km)
- Cedar Rapids #1 (24 km)
- Coggon (29 km)
- Cascade (34 km)
- Tipton (36 km)
- Lowden (40 km)
- Cedar Rapids Muni Airport (40 km)
- Manchester #2 (46 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.