Frost dates for Dubuque Regional Airport, IA
At Dubuque Regional Airport, the median last spring frost (32°F) is Apr 28 and the median first fall frost is Oct 11, for a typical growing season of 165 days. For a 90% chance that the last frost has passed, wait until May 12. Nearby ZIP codes are in USDA hardiness zone 5a.
- Apr 28Last spring frost (median)50% chance of 32°F after this date
- May 12Safer planting date10% chance of 32°F after this date
- Oct 11First fall frost (median)50% chance of 32°F by this date
- 165 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 21 |
| 32°F | Apr 13 | Apr 28 | May 12 |
| 28°F | Apr 2 | Apr 17 | May 3 |
| 24°F | Mar 21 | Apr 6 | Apr 22 |
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 20 | Oct 2 | Oct 14 |
| 32°F | Sep 28 | Oct 11 | Oct 23 |
| 28°F | Oct 8 | Oct 21 | Nov 2 |
| 24°F | Oct 17 | Oct 31 | Nov 13 |
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 | 128 days | 146 days | 163 days |
| 32°F | 146 days | 165 days | 186 days |
| 28°F | 166 days | 187 days | 206 days |
| 24°F | 184 days | 206 days | 227 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 |
|---|---|---|---|
| 52003 | 5a | -20 to -15°F | 5 km |
| 52068 | 5a | -20 to -15°F | 9 km |
| 52054 | 5a | -20 to -15°F | 12 km |
| 52079 | 5a | -20 to -15°F | 12 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 USW00094908, at 42.3978, -90.7036, elevation 322 m (1,056 ft).
- Data quality: Standard (24+ years of data), 30 years of freeze data.
- Average days per year at or below 32°F: 144.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Dubuque L&d 11 (17 km)
- Bellevue L&d 12 (28 km)
- Cascade (28 km)
- Maquoketa (36 km)
- Guttenberg L&d 10 (54 km)
- Anamosa 1 WNW (58 km)
- Anamosa 3 SSW (61 km)
- Manchester #2 (62 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.