Frost dates for Denmark Wastewater Plant, WI
At Denmark Wastewater Plant, the median last spring frost (32°F) is May 6 and the median first fall frost is Oct 12, for a typical growing season of 158 days. For a 90% chance that the last frost has passed, wait until May 20. Nearby ZIP codes are in USDA hardiness zone 5b.
- May 6Last spring frost (median)50% chance of 32°F after this date
- May 20Safer planting date10% chance of 32°F after this date
- Oct 12First fall frost (median)50% chance of 32°F by this date
- 158 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 4 | May 18 | Jun 1 |
| 32°F | Apr 22 | May 6 | May 20 |
| 28°F | Apr 9 | Apr 23 | May 9 |
| 24°F | Mar 29 | Apr 11 | 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 19 | Oct 1 | Oct 14 |
| 32°F | Sep 30 | Oct 12 | Oct 27 |
| 28°F | Oct 11 | Oct 26 | Nov 9 |
| 24°F | Oct 26 | Nov 5 | Nov 20 |
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 | 118 days | 136 days | 154 days |
| 32°F | 139 days | 158 days | 179 days |
| 28°F | 163 days | 183 days | 203 days |
| 24°F | 190 days | 208 days | 228 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 |
|---|---|---|---|
| 54208 | 5b | -15 to -10°F | 2 km |
| 54227 | 5b | -15 to -10°F | 8 km |
| 54215 | 5b | -15 to -10°F | 14 km |
| 54228 | 5b | -15 to -10°F | 15 km |
| 54311 | 5b | -15 to -10°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 USC00472055, at 44.3514, -87.8120, elevation 247 m (811 ft).
- Data quality: Representative (10+ years), 12 years of freeze data.
- Average days per year at or below 32°F: 156.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Kewaunee (27 km)
- Green Bay (29 km)
- Green Bay WFO (29 km)
- Brillion (30 km)
- Two Rivers (30 km)
- Green Bay Botanical (30 km)
- Manitowoc (32 km)
- Chilton (44 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.