Frost dates for Clinton #1, IA
At Clinton #1, the median last spring frost (32°F) is Apr 22 and the median first fall frost is Oct 16, for a typical growing season of 175 days. For a 90% chance that the last frost has passed, wait until May 8. Nearby ZIP codes are in USDA hardiness zones 5a to 5b.
- Apr 22Last spring frost (median)50% chance of 32°F after this date
- May 8Safer planting date10% chance of 32°F after this date
- Oct 16First fall frost (median)50% chance of 32°F by this date
- 175 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 18 | May 2 | May 17 |
| 32°F | Apr 9 | Apr 22 | May 8 |
| 28°F | Mar 31 | Apr 13 | Apr 29 |
| 24°F | Mar 17 | Apr 2 | Apr 18 |
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 23 | Oct 6 | Oct 18 |
| 32°F | Oct 2 | Oct 16 | Oct 28 |
| 28°F | Oct 11 | Oct 25 | Nov 5 |
| 24°F | Oct 24 | Nov 4 | Nov 18 |
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 | 134 days | 156 days | 174 days |
| 32°F | 155 days | 175 days | 193 days |
| 28°F | 175 days | 195 days | 215 days |
| 24°F | 195 days | 217 days | 238 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 |
|---|---|---|---|
| 52730 | 5b | -15 to -10°F | 6 km |
| 52757 | 5b | -15 to -10°F | 8 km |
| 61230 | 5b | -15 to -10°F | 8 km |
| 61242 | 5b | -15 to -10°F | 10 km |
| 52758 | 5b | -15 to -10°F | 16 km |
| 52750 | 5a | -20 to -15°F | 19 km |
| 52742 | 5b | -15 to -10°F | 22 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 USC00131635, at 41.7947, -90.2639, elevation 178 m (585 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 129.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Le Claire L&d 14 (27 km)
- Davenport WFO (33 km)
- Davenport (33 km)
- Maquoketa (46 km)
- Bellevue L&d 12 (54 km)
- Lowden (55 km)
- Tipton (72 km)
- Muscatine 2n (74 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.