Frost dates for Uw Arboretum - Madison, WI
At Uw Arboretum - Madison, the median last spring frost (32°F) is May 1 and the median first fall frost is Oct 9, for a typical growing season of 161 days. For a 90% chance that the last frost has passed, wait until May 17. Nearby ZIP codes are in USDA hardiness zones 5a to 5b.
- May 1Last spring frost (median)50% chance of 32°F after this date
- May 17Safer planting date10% chance of 32°F after this date
- Oct 9First fall frost (median)50% chance of 32°F by this date
- 161 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 29 | May 13 | May 30 |
| 32°F | Apr 18 | May 1 | May 17 |
| 28°F | Apr 7 | Apr 20 | May 3 |
| 24°F | Mar 29 | Apr 9 | Apr 22 |
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 17 | Oct 1 | Oct 12 |
| 32°F | Sep 26 | Oct 9 | Oct 24 |
| 28°F | Oct 5 | Oct 20 | Nov 3 |
| 24°F | Oct 16 | Nov 1 | Nov 14 |
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 | 119 days | 139 days | 159 days |
| 32°F | 140 days | 161 days | 179 days |
| 28°F | 163 days | 182 days | 202 days |
| 24°F | 184 days | 204 days | 223 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 |
|---|---|---|---|
| 53713 | 5a | -20 to -15°F | 3 km |
| 53726 | 5b | -15 to -10°F | 3 km |
| 53711 | 5b | -15 to -10°F | 4 km |
| 53715 | 5a | -20 to -15°F | 4 km |
| 53792 | 5a | -20 to -15°F | 4 km |
| 53706 | 5a | -20 to -15°F | 4 km |
| 53703 | 5b | -15 to -10°F | 6 km |
| 53575 | 5a | -20 to -15°F | 13 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 USC00470273, at 43.0411, -89.4286, elevation 265 m (870 ft).
- Data quality: Standard (24+ years of data), 27 years of freeze data.
- Average days per year at or below 32°F: 157.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Charmany Farm (5 km)
- Madison Dane Regional Airport (13 km)
- Stoughton (23 km)
- Arlington (30 km)
- Lodi (32 km)
- Mazomanie Wastewater Plant (35 km)
- Sauk City Wastewater Plant (35 km)
- Waterloo Wastewater Plant (40 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.