Wisconsin frost dates
The typical last spring frost ranges from Apr 19 in Milwaukee to May 14 in Sister Bay.
5 of the 5 Wisconsin cities listed have typical frost dates. The longest frost-free season is 192 days in Milwaukee; the shortest is 146 days in Wisconsin Dells. For a single address, look up your ZIP code: rural ZIPs use their nearest suitable station.
| City | Last spring frost | 1 in 10 after | First fall frost | 1 in 10 before | Hard freeze (28°F) | Season |
|---|---|---|---|---|---|---|
| Green Bay | Apr 30 | May 16 | Oct 9 | Sep 24 | Apr 17 / Oct 24 | 161 days |
| Madison | May 1 | May 16 | Oct 10 | Sep 26 | Apr 20 / Oct 22 | 160 days |
| Milwaukee | Apr 19 | May 2 | Oct 29 | Oct 15 | Apr 6 / Nov 8 | 192 days |
| Sister Bay | May 14 | May 28 | Oct 18 | Oct 1 | May 1 / Nov 1 | 155 days |
| Wisconsin Dells | May 8 | May 22 | Oct 3 | Sep 21 | Apr 28 / Oct 14 | 146 days |
Reading the table: Madison
In Madison, the last spring frost typically comes around May 1: in half of years it is earlier, in half later. In 1 year in 10 it comes after May 16, 15 days later, so tender plants set out after that date have a 90% chance of escaping frost. In fall, the first frost typically arrives around Oct 10, and in 1 year in 10 before Sep 26. Hard freezes (28°F) usually end earlier in spring and start later in fall: around Apr 20 and Oct 22 in Madison.
Frost dates at more Wisconsin weather stations
NOAA stations across Wisconsin used by our ZIP code lookup, named for the town they are in.
| Station | Elevation | Last spring frost | First fall frost |
|---|---|---|---|
| Afton - Janesville Wwtp | 762 ft | Apr 26 (1 in 10 after May 11) | Oct 15 (before Oct 1) |
| Amery | 1,070 ft | May 5 (1 in 10 after May 21) | Oct 4 (before Sep 21) |
| Antigo | 1,519 ft | May 14 (1 in 10 after May 28) | Sep 30 (before Sep 14) |
| Appleton | 792 ft | May 4 (1 in 10 after May 20) | Oct 6 (before Sep 23) |
| Arlington | 1,052 ft | May 4 (1 in 10 after May 18) | Oct 6 (before Sep 23) |
| Beaver Dam Wwtp | 861 ft | May 2 (1 in 10 after May 16) | Oct 9 (before Sep 25) |
| Beloit | 788 ft | May 1 (1 in 10 after May 16) | Oct 12 (before Sep 28) |
| Blair | 855 ft | May 9 (1 in 10 after May 23) | Oct 1 (before Sep 18) |
| Brodhead Wwtp | 780 ft | Apr 29 (1 in 10 after May 14) | Oct 12 (before Sep 28) |
| Brule RS | 1,000 ft | May 24 (1 in 10 after Jun 6) | Sep 26 (before Sep 9) |
| Burlington | 751 ft | May 5 (1 in 10 after May 23) | Oct 9 (before Sep 24) |
| Chilton | 840 ft | May 1 (1 in 10 after May 17) | Oct 14 (before Sep 29) |
| Clintonville | 802 ft | May 4 (1 in 10 after May 19) | Oct 6 (before Sep 21) |
| Cumberland | 1,240 ft | May 5 (1 in 10 after May 18) | Oct 4 (before Sep 23) |
| Dodgeville Wwtp | 1,118 ft | May 3 (1 in 10 after May 17) | Oct 7 (before Sep 25) |
| Eagle Rvr | 1,623 ft | May 25 (1 in 10 after Jun 6) | Sep 24 (before Sep 8) |
| Eau Claire Rgnl Airport | 885 ft | May 8 (1 in 10 after May 21) | Oct 4 (before Sep 20) |
| Ellsworth 1E | 1,030 ft | May 13 (1 in 10 after May 27) | Sep 29 (before Sep 15) |
| Fond Du Lac Co Airport | 809 ft | May 1 (1 in 10 after May 17) | Oct 10 (before Sep 27) |
| Fond Du Lac Wwtp | 750 ft | May 1 (1 in 10 after May 17) | Oct 12 (before Sep 28) |
| Gays Mills | 689 ft | May 3 (1 in 10 after May 18) | Oct 7 (before Sep 25) |
| Genoa Dam 8 | 639 ft | Apr 22 (1 in 10 after May 5) | Oct 17 (before Oct 4) |
| Germantown | 850 ft | May 6 (1 in 10 after May 25) | Oct 8 (before Sep 26) |
| Hancock Exp Farm | 1,092 ft | May 10 (1 in 10 after May 24) | Oct 3 (before Sep 20) |
| Hartford Wwtp | 961 ft | May 8 (1 in 10 after May 24) | Oct 3 (before Sep 20) |
| Hillsboro | 940 ft | May 5 (1 in 10 after May 18) | Oct 4 (before Sep 23) |
| Horicon Wwtp | 881 ft | May 1 (1 in 10 after May 19) | Oct 10 (before Sep 27) |
| Kenosha | 600 ft | Apr 19 (1 in 10 after May 3) | Oct 26 (before Oct 11) |
| La Crosse Muni Airport | 652 ft | Apr 23 (1 in 10 after May 6) | Oct 17 (before Oct 3) |
| Lake Geneva Wwtp | 846 ft | Apr 25 (1 in 10 after May 10) | Oct 21 (before Oct 5) |
| Lancaster 4 Wsw | 1,040 ft | Apr 27 (1 in 10 after May 11) | Oct 11 (before Sep 27) |
| Laona 6 Sw | 1,695 ft | May 19 (1 in 10 after Jun 2) | Sep 29 (before Sep 15) |
| Lone Rock Tri Co Airport | 717 ft | Apr 30 (1 in 10 after May 14) | Oct 9 (before Sep 25) |
| Luck | 1,220 ft | May 6 (1 in 10 after May 20) | Oct 4 (before Sep 19) |
| Marshfield Exp Farm | 1,237 ft | May 5 (1 in 10 after May 20) | Oct 5 (before Sep 22) |
| Mather 3 Nw | 978 ft | May 6 (1 in 10 after May 20) | Oct 3 (before Sep 19) |
| Mauston 1 Se | 865 ft | May 2 (1 in 10 after May 15) | Oct 7 (before Sep 26) |
| Medford | 1,470 ft | May 11 (1 in 10 after May 26) | Oct 1 (before Sep 17) |
| Montello | 786 ft | May 3 (1 in 10 after May 18) | Oct 5 (before Sep 22) |
| Mt Mary College | 715 ft | Apr 26 (1 in 10 after May 12) | Oct 18 (before Oct 2) |
| Neillsville 3ESE | 1,080 ft | May 10 (1 in 10 after May 25) | Oct 1 (before Sep 18) |
| Oconomowoc Wwtp | 858 ft | Apr 30 (1 in 10 after May 17) | Oct 12 (before Sep 29) |
| Oconto 4 W | 660 ft | May 9 (1 in 10 after May 23) | Oct 6 (before Sep 22) |
| Oshkosh Wittman Airport | 782 ft | Apr 30 (1 in 10 after May 13) | Oct 13 (before Sep 29) |
| Owen 1E | 1,238 ft | May 13 (1 in 10 after May 29) | Sep 26 (before Sep 12) |
| Plymouth Wwtp | 828 ft | May 3 (1 in 10 after May 20) | Oct 10 (before Sep 28) |
| Prairie Du Chien | 658 ft | Apr 28 (1 in 10 after May 11) | Oct 12 (before Sep 27) |
| Rice Lake | 1,103 ft | May 8 (1 in 10 after May 23) | Oct 2 (before Sep 19) |
| Ridgeland 1NNE | 1,080 ft | May 10 (1 in 10 after May 26) | Sep 29 (before Sep 13) |
| River Falls | 940 ft | May 11 (1 in 10 after May 26) | Oct 1 (before Sep 19) |
| Rosholt 9 Nne | 1,183 ft | May 6 (1 in 10 after May 21) | Oct 5 (before Sep 22) |
| Sparta | 782 ft | May 9 (1 in 10 after May 22) | Oct 1 (before Sep 18) |
| Spooner Ag Res Stn | 1,100 ft | May 14 (1 in 10 after May 29) | Sep 28 (before Sep 14) |
| Stevens Pt | 1,079 ft | May 4 (1 in 10 after May 20) | Oct 7 (before Sep 24) |
| Superior | 607 ft | May 6 (1 in 10 after May 25) | Oct 9 (before Sep 24) |
| Viroqua | 1,255 ft | May 7 (1 in 10 after May 21) | Oct 2 (before Sep 18) |
| Waukesha Wwtp | 789 ft | May 1 (1 in 10 after May 18) | Oct 13 (before Sep 29) |
| Waupaca | 837 ft | May 8 (1 in 10 after May 21) | Oct 6 (before Sep 23) |
| Wausau Downtown Airport | 1,181 ft | May 6 (1 in 10 after May 21) | Oct 4 (before Sep 21) |
| Wisconsin Rapids Alexander Fld | 1,019 ft | May 8 (1 in 10 after May 22) | Oct 1 (before Sep 19) |
32°F dates from NOAA 1991-2020 freeze probabilities for each city's station. "1 in 10 after": a 10% chance of a later spring frost (planting is 90% safe after it). How to read frost dates.