Frost dates for Reedsburg, WI
At Reedsburg, the median last spring frost (32°F) is May 2 and the median first fall frost is Oct 7, for a typical growing season of 156 days. For a 90% chance that the last frost has passed, wait until May 16. Nearby ZIP codes are in USDA hardiness zone 5a.
- May 2Last spring frost (median)50% chance of 32°F after this date
- May 16Safer planting date10% chance of 32°F after this date
- Oct 7First fall frost (median)50% chance of 32°F by this date
- 156 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 30 | May 13 | May 26 |
| 32°F | Apr 18 | May 2 | May 16 |
| 28°F | Apr 7 | Apr 20 | May 5 |
| 24°F | Mar 27 | Apr 9 | Apr 24 |
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 15 | Sep 29 | Oct 9 |
| 32°F | Sep 23 | Oct 7 | Oct 20 |
| 28°F | Oct 2 | Oct 18 | Oct 31 |
| 24°F | Oct 16 | Oct 30 | 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 | 117 days | 137 days | 155 days |
| 32°F | 138 days | 156 days | 176 days |
| 28°F | 158 days | 178 days | 198 days |
| 24°F | 181 days | 202 days | 221 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 |
|---|---|---|---|
| 53959 | 5a | -20 to -15°F | 1 km |
| 53941 | 5a | -20 to -15°F | 13 km |
| 53942 | 5a | -20 to -15°F | 15 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 USC00477052, at 43.5231, -90.0003, elevation 282 m (926 ft).
- Data quality: Representative (10+ years), 17 years of freeze data.
- Average days per year at or below 32°F: 154.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Rock Springs 3 SW (9 km)
- Wisconsin Dells (21 km)
- Baraboo (23 km)
- Mauston 1 SE (30 km)
- Hillsboro (31 km)
- Hillsboro 2sw (33 km)
- Sauk City Wastewater Plant (36 km)
- Lone Rock Tri Co Airport (38 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.