Frost dates for Rock Springs 3 SW, WI
At Rock Springs 3 SW, the median last spring frost (32°F) is Apr 24 and the median first fall frost is Oct 20, for a typical growing season of 178 days. For a 90% chance that the last frost has passed, wait until May 7. Nearby ZIP codes are in USDA hardiness zone 5a.
- Apr 24Last spring frost (median)50% chance of 32°F after this date
- May 7Safer planting date10% chance of 32°F after this date
- Oct 20First fall frost (median)50% chance of 32°F by this date
- 178 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 22 | May 4 | May 18 |
| 32°F | Apr 10 | Apr 24 | May 7 |
| 28°F | Apr 1 | Apr 13 | Apr 27 |
| 24°F | Mar 18 | Apr 3 | Apr 17 |
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 8 | Oct 24 |
| 32°F | Oct 1 | Oct 20 | Nov 1 |
| 28°F | Oct 17 | Oct 31 | Nov 12 |
| 24°F | Oct 29 | Nov 8 | 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 | 133 days | 154 days | 175 days |
| 32°F | 157 days | 178 days | 198 days |
| 28°F | 180 days | 201 days | 220 days |
| 24°F | 201 days | 219 days | 239 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 |
|---|---|---|---|
| 53961 | 5a | -20 to -15°F | 3 km |
| 53943 | 5a | -20 to -15°F | 8 km |
| 53951 | 5a | -20 to -15°F | 10 km |
| 53937 | 5a | -20 to -15°F | 16 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 USC00477319, at 43.4450, -89.9697, elevation 384 m (1,260 ft).
- Data quality: Representative (10+ years), 10 years of freeze data.
- Average days per year at or below 32°F: 145.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Reedsburg (9 km)
- Baraboo (20 km)
- Wisconsin Dells (24 km)
- Sauk City Wastewater Plant (28 km)
- Lone Rock Tri Co Airport (31 km)
- Mazomanie Wastewater Plant (33 km)
- Richland Center (36 km)
- Hillsboro (37 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.