Frost dates for Bayfield 6 N, WI
At Bayfield 6 N, the median last spring frost (32°F) is May 20 and the median first fall frost is Oct 8, for a typical growing season of 141 days. For a 90% chance that the last frost has passed, wait until Jun 5. Nearby ZIP codes are in USDA hardiness zones 5a to 5b.
- May 20Last spring frost (median)50% chance of 32°F after this date
- Jun 5Safer planting date10% chance of 32°F after this date
- Oct 8First fall frost (median)50% chance of 32°F by this date
- 141 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 19 | Jun 3 | Jun 17 |
| 32°F | May 2 | May 20 | Jun 5 |
| 28°F | Apr 19 | May 3 | May 20 |
| 24°F | Apr 6 | Apr 22 | May 6 |
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 12 | Sep 26 | Oct 10 |
| 32°F | Sep 21 | Oct 8 | Oct 26 |
| 28°F | Oct 5 | Oct 24 | Nov 7 |
| 24°F | Oct 21 | Nov 3 | Nov 17 |
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 | 95 days | 114 days | 135 days |
| 32°F | 117 days | 141 days | 164 days |
| 28°F | 148 days | 172 days | 194 days |
| 24°F | 175 days | 196 days | 217 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 |
|---|---|---|---|
| 54814 | 5a | -20 to -15°F | 7 km |
| 54850 | 5b | -15 to -10°F | 20 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 USC00470603, at 46.8833, -90.8167, elevation 250 m (820 ft).
- Data quality: Representative (10+ years), 13 years of freeze data.
- Average days per year at or below 32°F: 177.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Bayfield Fish Hatchery (11 km)
- Madeline Island (12 km)
- Ashland 3s (38 km)
- Ashland Kennedy Mem Airport (38 km)
- Port Wing (45 km)
- Saxon 1wsw (53 km)
- Mellen 4 NE (59 km)
- Hurley (67 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.