Frost dates for Big Falls Hydro, WI
At Big Falls Hydro, the median last spring frost (32°F) is May 7 and the median first fall frost is Oct 3, for a typical growing season of 147 days. For a 90% chance that the last frost has passed, wait until May 22. Nearby ZIP codes are in USDA hardiness zone 4a.
- May 7Last spring frost (median)50% chance of 32°F after this date
- May 22Safer planting date10% chance of 32°F after this date
- Oct 3First fall frost (median)50% chance of 32°F by this date
- 147 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 | May 6 | May 19 | Jun 1 |
| 32°F | Apr 25 | May 7 | May 22 |
| 28°F | Apr 13 | Apr 28 | May 11 |
| 24°F | Apr 3 | Apr 17 | May 1 |
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 10 | Sep 24 | Oct 7 |
| 32°F | Sep 18 | Oct 3 | Oct 18 |
| 28°F | Sep 28 | Oct 14 | Oct 30 |
| 24°F | Oct 11 | Oct 28 | Nov 10 |
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 | 106 days | 127 days | 146 days |
| 32°F | 127 days | 147 days | 167 days |
| 28°F | 147 days | 169 days | 192 days |
| 24°F | 171 days | 193 days | 212 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 |
|---|---|---|---|
| 54526 | 4a | -30 to -25°F | 8 km |
| 54563 | 4a | -30 to -25°F | 11 km |
| 54530 | 4a | -30 to -25°F | 19 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 USC00470773, at 45.5556, -90.9592, elevation 367 m (1,205 ft).
- Data quality: Representative (10+ years), 20 years of freeze data.
- Average days per year at or below 32°F: 190.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Ladysmith 3w (16 km)
- Winter (27 km)
- Jump River 3e (28 km)
- Weyerhaeuser 1n (38 km)
- Holcombe (39 km)
- Couderay 7 W (47 km)
- Prentice #2 (51 km)
- Butternut 3sw (57 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.