Wisconsin frost dates: Last spring and first autumn frost at every NOAA station, 1991-2020
Across Wisconsin's 204 NOAA stations with frost dates, the median last spring frost (32°F) runs from April 19 in Kenosha station to June 3 in North Pelican; for half of its places it comes after May 5.
- Typical last spring frost
- May 5median of 164 places
- Typical first autumn frost
- October 7median of 164 places
- Earliest last frost
- April 19Kenosha station
- Latest last frost
- June 3North Pelican
When is the last frost in Wisconsin, town by town?
Each date is NOAA's: "after May 5 in half of years" means the last 32°F night of spring came after May 5 in half of the years 1991-2020. By the 1-in-10 date, the last frost has passed in nine years out of ten.
Find your town in the list, or look up a ZIP code for the stations nearest it.
| Place or station | Last frost (median) | 1 in 10 after | First frost (median) | 1 in 10 before | Growing season | Zone |
|---|---|---|---|---|---|---|
| Kenosha station | April 19 | May 3 | October 26 | October 11 | 189 days | 6a |
| MilwaukeeMilwaukee Mitchell Airport | April 19 | May 2 | October 29 | October 15 | 192 days | 6a |
| Racine station | April 20 | May 6 | October 24 | October 8 | 184 days | 6a |
| GenoaGenoa Dam 8 | April 22 | May 5 | October 17 | October 4 | 178 days | 5a |
| South MilwaukeeSouth Milwaukee Wastewater Treatment Plant | April 22 | May 8 | October 26 | October 10 | 184 days | – |
| Steuben4 mi SE | April 22 | May 8 | October 20 | October 5 | 179 days | – |
| GraftonGrafton Wastewater Treatment Plant | April 23 | May 9 | October 24 | October 8 | 182 days | – |
| La CrosseLa Crosse Regional Airport | April 23 | May 6 | October 17 | October 3 | 177 days | 5a |
| Eau Claire (3 mi SW) | April 24 | May 7 | October 14 | September 26 | 170 days | 5a |
| LynxvilleLynxville Dam 9 | April 24 | May 8 | October 17 | October 4 | 175 days | 5a |
| Oshkosh station | April 24 | May 8 | October 20 | October 4 | 178 days | 5b |
| RacineRacine Batten Airport | April 24 | May 10 | October 24 | October 10 | 180 days | 6a |
| Rock Springs3 mi SW | April 24 | May 7 | October 20 | October 1 | 178 days | – |
| JeffersonJefferson Wastewater Treatment Plant | April 25 | May 9 | October 18 | October 2 | 173 days | 5b |
| Lake GenevaLake Geneva Wastewater Treatment Plant | April 25 | May 10 | October 21 | October 5 | 179 days | – |
| Sheboygan station | April 25 | May 11 | October 23 | October 9 | 179 days | – |
| Afton - Janesville Wastewater Treatment Plant | April 26 | May 11 | October 15 | October 1 | 170 days | 5b |
| WauwatosaMount Mary College | April 26 | May 12 | October 18 | October 2 | 173 days | 6a |
| West Allis | April 26 | May 12 | October 22 | October 7 | 177 days | – |
| Cashton | April 27 | May 11 | October 14 | October 1 | 170 days | 5a |
| Fond Du Lac (2 mi SW) | April 27 | May 11 | October 19 | October 2 | 174 days | – |
| La Crosse Weather Office | April 27 | May 12 | October 13 | September 28 | 167 days | 5a |
| Lancaster4 mi WSW | April 27 | May 11 | October 11 | September 27 | 166 days | 5a |
| MonroeMonroe Wastewater Treatment Plant | April 27 | May 12 | October 14 | September 29 | 170 days | – |
| Port Washington | April 27 | May 14 | October 22 | October 6 | 176 days | 5b |
| Two Rivers | April 27 | May 10 | October 21 | October 4 | 175 days | 5b |
| AlmaAlma Dam 4 | April 28 | May 9 | October 14 | September 29 | 168 days | 5a |
| Charmany Farm | April 28 | May 11 | October 15 | September 29 | 169 days | 5b |
| DelavanDelavan Wastewater Treatment Plant | April 28 | May 14 | October 14 | September 28 | 168 days | – |
| Fort Atkinson | April 28 | May 17 | October 13 | September 29 | 166 days | 5a |
| HustisfordHustisford Wastewater Treatment Plant | April 28 | May 13 | October 10 | September 26 | 164 days | – |
| KenoshaKenosha Regional Airport | April 28 | May 13 | October 19 | October 1 | 174 days | 5b |
| PortagePortage Wastewater Treatment Plant | April 28 | May 12 | October 10 | September 26 | 164 days | 5a |
| Prairie du ChienPrairie Du Chien | April 28 | May 11 | October 12 | September 27 | 166 days | 5a |
| WatertownWatertown Wastewater Treatment Plant | April 28 | May 13 | October 12 | September 28 | 167 days | 5a |
| BrodheadBrodhead Wastewater Treatment Plant | April 29 | May 14 | October 12 | September 28 | 165 days | 5a |
| Lake MillsLake Mills Wastewater Treatment Plant | April 29 | May 13 | October 14 | September 29 | 167 days | 5b |
| TrempealeauTrempealeau Dam 6 | April 29 | May 13 | October 11 | September 26 | 165 days | 5a |
| BrookfieldBrookfield Wastewater Treatment Plant | April 30 | May 15 | October 14 | September 28 | 164 days | – |
| ClintonClinton Wastewater Treatment Plant | April 30 | May 17 | October 10 | September 26 | 161 days | 5a |
| Green BayGreen Bay A S International Airport | April 30 | May 16 | October 9 | September 24 | 161 days | 5a |
| Jackson | April 30 | May 15 | October 15 | October 1 | 167 days | 5b |
| Lone RockLone Rock Tri County Airport | April 30 | May 14 | October 9 | September 25 | 161 days | 4b |
| Manitowoc | April 30 | May 15 | October 20 | October 3 | 171 days | 5b |
| OconomowocOconomowoc Wastewater Treatment Plant | April 30 | May 17 | October 12 | September 29 | 164 days | 5b |
| OshkoshOshkosh Wittman Airport | April 30 | May 13 | October 13 | September 29 | 165 days | 5b |
| Paddock Lake | April 30 | May 16 | October 15 | September 30 | 167 days | – |
| Pell Lake | April 30 | May 16 | October 13 | September 28 | 164 days | – |
| Platteville | April 30 | May 13 | October 13 | September 29 | 166 days | 5a |
| Richfield3 mi SSW | April 30 | May 16 | October 16 | October 1 | 167 days | 5b |
| Stoughton | April 30 | May 15 | October 11 | September 28 | 163 days | 5b |
| WaterlooWaterloo Wastewater Treatment Plant | April 30 | May 15 | October 9 | September 27 | 163 days | – |
| AshwaubenonGreen Bay Weather Office | May 1 | May 16 | October 11 | September 26 | 160 days | – |
| Beloit | May 1 | May 16 | October 12 | September 28 | 162 days | 5b |
| BerlinBerlin Wastewater Treatment Plant | May 1 | May 16 | October 8 | September 24 | 158 days | 5a |
| Chilton | May 1 | May 17 | October 14 | September 29 | 162 days | 5b |
| Durand | May 1 | May 15 | October 10 | September 26 | 162 days | – |
| Fond Du Lac Wastewater Treatment Plant | May 1 | May 17 | October 12 | September 28 | 162 days | 5b |
| Fond du LacFond Du Lac County Airport | May 1 | May 17 | October 10 | September 27 | 160 days | 5b |
| HoriconHoricon Wastewater Treatment Plant | May 1 | May 19 | October 10 | September 27 | 158 days | 5a |
| Jim Falls3 mi NW | May 1 | May 16 | October 8 | September 22 | 158 days | – |
| Kewaunee | May 1 | May 17 | October 18 | October 2 | 168 days | 6a |
| Lodi | May 1 | May 15 | October 10 | September 27 | 162 days | 5a |
| MadisonMadison Dane County Regional Airport | May 1 | May 16 | October 10 | September 26 | 160 days | 5b |
| Necedah5 mi WNW | May 1 | May 14 | October 3 | September 20 | 157 days | 4b |
| Ripon5 mi NE | May 1 | May 14 | October 11 | September 26 | 163 days | – |
| Town Of Westford | May 1 | May 16 | October 11 | September 27 | 163 days | – |
| Uw Arboretum - Madison | May 1 | May 17 | October 9 | September 26 | 161 days | 5a |
| WaukeshaWaukesha Wastewater Treatment Plant | May 1 | May 18 | October 13 | September 29 | 162 days | 5b |
| West BendWest Bend Public Works | May 1 | May 18 | October 12 | September 28 | 161 days | – |
| Beaver DamBeaver Dam Wastewater Treatment Plant | May 2 | May 16 | October 9 | September 25 | 157 days | 5a |
| Mauston1 mi SE | May 2 | May 15 | October 7 | September 26 | 158 days | 5a |
| Reedsburg | May 2 | May 16 | October 7 | September 23 | 156 days | 5a |
| Sheboygan Wastewater Treatment Plant | May 2 | May 19 | October 21 | October 3 | 169 days | – |
| Whitewater | May 2 | May 20 | October 9 | September 25 | 157 days | 5b |
| BoscobelBoscobel Airport | May 3 | May 18 | October 7 | September 25 | 155 days | 4b |
| DarlingtonDarlington Wastewater Treatment Plant | May 3 | May 19 | October 4 | September 20 | 153 days | – |
| DodgevilleDodgeville Wastewater Treatment Plant | May 3 | May 17 | October 7 | September 25 | 157 days | 5a |
| Gays Mills | May 3 | May 18 | October 7 | September 25 | 156 days | 4a |
| Hales CornersHales Corners/Whitnall Park/Bo | May 3 | May 19 | October 14 | September 30 | 162 days | 5b |
| HinghamHingham Wastewater Treatment Plant | May 3 | May 18 | October 16 | October 2 | 165 days | 5b |
| Montello | May 3 | May 18 | October 5 | September 22 | 153 days | 5a |
| PlymouthPlymouth Wastewater Treatment Plant | May 3 | May 20 | October 10 | September 28 | 159 days | 5b |
| Sullivan3 mi SE | May 3 | May 21 | October 9 | September 25 | 157 days | 5b |
| Appleton | May 4 | May 20 | October 6 | September 23 | 154 days | 5b |
| Arlington | May 4 | May 18 | October 6 | September 23 | 154 days | 5a |
| Clintonville | May 4 | May 19 | October 6 | September 21 | 154 days | 5a |
| Marinette | May 4 | May 20 | October 11 | September 29 | 160 days | 5b |
| New London | May 4 | May 19 | October 6 | September 22 | 153 days | 5a |
| Sauk CitySauk City Wastewater Treatment Plant | May 4 | May 18 | October 6 | September 23 | 155 days | – |
| St. Croix FallsSt Croix Falls | May 4 | May 18 | October 8 | September 24 | 156 days | 4a |
| Stevens Point | May 4 | May 20 | October 7 | September 24 | 155 days | 5a |
| West Bend station | May 4 | May 21 | October 11 | September 26 | 157 days | – |
| Amery | May 5 | May 21 | October 4 | September 21 | 151 days | 4b |
| Baraboo | May 5 | May 21 | October 5 | September 22 | 152 days | 5a |
| BelgiumBelgium Wastewater Treatment Plant | May 5 | May 22 | October 12 | September 27 | 159 days | – |
| Bloomer | May 5 | May 19 | October 3 | September 20 | 151 days | 4b |
| Burlington | May 5 | May 23 | October 9 | September 24 | 156 days | 5b |
| Cumberland | May 5 | May 18 | October 4 | September 23 | 152 days | 4b |
| Dodge | May 5 | May 19 | October 5 | September 21 | 152 days | – |
| Hillsboro | May 5 | May 18 | October 4 | September 23 | 153 days | 4b |
| Holcombe | May 5 | May 21 | October 2 | September 19 | 149 days | – |
| MarshfieldMarshfield Municipal Airport | May 5 | May 20 | October 5 | September 21 | 152 days | 5a |
| Marshfield Experiment Farm | May 5 | May 20 | October 5 | September 22 | 150 days | 5a |
| Richland Center | May 5 | May 19 | October 6 | September 24 | 154 days | 4b |
| RochesterRochester Wastewater Treatment Plant | May 5 | May 23 | October 10 | September 26 | 156 days | – |
| SaukvilleSaukville Wastewater Treatment Plant | May 5 | May 19 | October 11 | September 29 | 158 days | – |
| SheboyganSheboygan County Mem Airport | May 5 | May 21 | October 8 | September 26 | 154 days | 5b |
| SlingerSlinger Wastewater Treatment Plant | May 5 | May 20 | October 5 | September 22 | 152 days | – |
| Union Grove | May 5 | May 20 | October 8 | September 27 | 156 days | 5b |
| Baldwin | May 6 | May 21 | October 2 | September 18 | 148 days | – |
| Brillion | May 6 | May 21 | October 6 | September 23 | 151 days | 5b |
| Cashton (3 mi NNW) | May 6 | May 20 | October 3 | September 20 | 150 days | – |
| Dalton | May 6 | May 22 | October 2 | September 20 | 150 days | – |
| DenmarkDenmark Wastewater Treatment Plant | May 6 | May 20 | October 12 | September 30 | 158 days | – |
| ForestvilleForestville-4 mi E | May 6 | May 20 | October 17 | October 1 | 163 days | 5b |
| Germantown | May 6 | May 25 | October 8 | September 26 | 154 days | 5b |
| Luck | May 6 | May 20 | October 4 | September 19 | 149 days | 4b |
| Mather (3 mi NW) | May 6 | May 20 | October 3 | September 19 | 148 days | 4b |
| Rosholt9 mi NNE | May 6 | May 21 | October 5 | September 22 | 150 days | 4b |
| Superior | May 6 | May 25 | October 9 | September 24 | 154 days | 5a |
| WausauWausau Asos | May 6 | May 21 | October 4 | September 21 | 150 days | 5a |
| AugustaAugusta Ranger Station | May 7 | May 20 | October 1 | September 17 | 146 days | 4b |
| Big Falls Hydro | May 7 | May 22 | October 3 | September 18 | 147 days | 4a |
| Green Bay Botanical | May 7 | May 22 | October 9 | September 23 | 154 days | – |
| MazomanieMazomanie Wastewater Treatment Plant | May 7 | May 22 | October 1 | September 18 | 148 days | – |
| StanleyStanley Wastewater Treatment Plant | May 7 | May 21 | October 3 | September 20 | 147 days | 4b |
| Viroqua | May 7 | May 21 | October 2 | September 18 | 148 days | 5a |
| Eau ClaireChippewa Valley Regional Airport | May 8 | May 21 | October 4 | September 20 | 149 days | 4b |
| HartfordHartford Wastewater Treatment Plant | May 8 | May 24 | October 3 | September 20 | 148 days | 5a |
| Markesan | May 8 | May 23 | October 2 | September 19 | 144 days | – |
| Rice Lake | May 8 | May 23 | October 2 | September 19 | 145 days | 4b |
| Sturgeon BaySturgeon Bay Experiment Farm | May 8 | May 21 | October 13 | September 28 | 157 days | 5b |
| Waupaca | May 8 | May 21 | October 6 | September 23 | 151 days | 5a |
| Wisconsin Dells | May 8 | May 22 | October 3 | September 21 | 146 days | 4b |
| Wisconsin RapidsWisconsin Rapids Alexander Field | May 8 | May 22 | October 1 | September 19 | 145 days | 5a |
| Blair | May 9 | May 23 | October 1 | September 18 | 143 days | 4b |
| Friendship | May 9 | May 23 | October 3 | September 19 | 147 days | 4b |
| Menomonie | May 9 | May 24 | October 1 | September 19 | 143 days | 4b |
| Oconto4 mi W | May 9 | May 23 | October 6 | September 22 | 150 days | 5a |
| Shawano2 mi SSW | May 9 | May 24 | October 2 | September 18 | 144 days | 5a |
| Sparta | May 9 | May 22 | October 1 | September 18 | 144 days | 4b |
| Weyerhaeuser1 mi N | May 9 | May 27 | September 29 | September 14 | 140 days | – |
| Wisconsin Rapids station | May 9 | May 24 | September 30 | September 17 | 142 days | 5a |
| HancockHancock Experiment Farm | May 10 | May 24 | October 3 | September 20 | 146 days | 5a |
| Minong5 mi WSW | May 10 | May 26 | October 4 | September 21 | 144 days | – |
| Mondovi | May 10 | May 25 | October 2 | September 19 | 144 days | 4b |
| Neillsville3 mi ESE | May 10 | May 25 | October 1 | September 18 | 144 days | 4b |
| Rice Reservoir Tomahawk-2 | May 10 | May 27 | October 4 | September 21 | 146 days | 4b |
| Ridgeland1 mi NNE | May 10 | May 26 | September 29 | September 13 | 140 days | 4b |
| Danbury | May 11 | May 28 | September 30 | September 15 | 138 days | 4a |
| Grantsburg | May 11 | May 28 | October 1 | September 16 | 141 days | 4a |
| Medford | May 11 | May 26 | October 1 | September 17 | 141 days | 4b |
| Merrill | May 11 | May 27 | September 30 | September 17 | 139 days | 4b |
| Peshtigo | May 11 | May 26 | October 5 | September 21 | 145 days | 5a |
| River Falls | May 11 | May 26 | October 1 | September 19 | 143 days | 4b |
| Hillsboro (2 mi SW) | May 12 | May 26 | September 29 | September 17 | 138 days | – |
| Solon Springs | May 12 | May 27 | October 2 | September 17 | 142 days | 4a |
| Ellsworth1 mi E | May 13 | May 27 | September 29 | September 15 | 139 days | 4b |
| Owen1 mi E | May 13 | May 29 | September 26 | September 12 | 136 days | 4b |
| Stockbridge-Munsee Reservation | May 13 | May 26 | September 30 | September 17 | 141 days | – |
| Willow Reservoir | May 13 | May 27 | October 3 | September 16 | 141 days | 4a |
| Antigo | May 14 | May 28 | September 30 | September 14 | 139 days | – |
| EphraimEphraim 1 mi NE-Wastewater Treatment Plant | May 14 | May 28 | October 18 | October 1 | 155 days | – |
| SpoonerSpooner Agricultural Reservoir Station | May 14 | May 29 | September 28 | September 14 | 135 days | 4a |
| Suring | May 14 | May 29 | October 1 | September 19 | 139 days | 4b |
| Park FallsPark Falls DNR Headquarters | May 15 | May 30 | September 28 | September 16 | 134 days | – |
| Washington Island | May 15 | May 31 | October 14 | September 28 | 152 days | 6a |
| Clam Lake4 mi W | May 16 | May 27 | September 30 | September 17 | 136 days | – |
| Necedah station | May 17 | June 1 | September 25 | September 12 | 131 days | – |
| Pattison Ranger Staion | May 18 | June 3 | October 3 | September 20 | 135 days | – |
| Laona6 mi SW | May 19 | June 2 | September 29 | September 15 | 131 days | 4b |
| St Germain | May 19 | May 31 | October 3 | September 18 | 136 days | – |
| Winter | May 19 | June 3 | September 27 | September 8 | 129 days | 4a |
| Ashland (3 mi S) | May 20 | June 3 | October 2 | September 19 | 133 days | – |
| Bayfield (6 mi N) | May 20 | June 5 | October 8 | September 21 | 141 days | – |
| Drummond | May 20 | June 2 | October 1 | September 19 | 132 days | – |
| Jump River (3 mi E) | May 20 | June 4 | September 23 | September 6 | 125 days | 4a |
| Madeline Island | May 20 | June 3 | October 9 | September 25 | 140 days | 5a |
| Butternut3 mi SW | May 22 | June 4 | September 24 | September 10 | 126 days | 4a |
| Gordon | May 22 | June 4 | September 26 | September 11 | 126 days | 4a |
| Hayward Ranger Station | May 22 | June 6 | September 23 | September 3 | 124 days | 4a |
| Lakewood3 mi NE | May 22 | June 3 | September 28 | September 12 | 129 days | – |
| Rhinelander station | May 22 | June 4 | September 24 | September 9 | 125 days | 4a |
| AshlandAshland Kennedy Memorial Airport | May 23 | June 6 | September 29 | September 14 | 125 days | 5a |
| BayfieldBayfield Fish Hatchery | May 23 | June 5 | October 2 | September 17 | 131 days | – |
| HaywardHayward Municipal Airport | May 23 | June 6 | September 22 | September 5 | 122 days | 4a |
| Minocqua | May 23 | June 6 | September 27 | September 9 | 127 days | 4a |
| PrenticePrentice #2 | May 23 | June 6 | September 23 | September 5 | 124 days | – |
| Rhinelander (4 mi NE) | May 23 | June 5 | September 23 | September 7 | 124 days | – |
| Saxon1 mi WSW | May 23 | June 5 | October 1 | September 18 | 132 days | 4b |
| BruleBrule Ranger Station | May 24 | June 6 | September 26 | September 9 | 124 days | 4a |
| Florence | May 24 | June 8 | September 25 | September 7 | 121 days | 4b |
| GoodmanGoodman Sanitary Dist | May 24 | June 7 | September 30 | September 16 | 128 days | – |
| Hurley | May 24 | June 7 | September 28 | September 13 | 128 days | 4b |
| Eagle River | May 25 | June 6 | September 24 | September 8 | 121 days | 4b |
| Rest Lake | May 25 | June 9 | September 21 | September 3 | 117 days | 4a |
| CrivitzCrivitz High Falls | May 26 | June 11 | September 22 | September 6 | 118 days | – |
| Mellen4 mi NE | May 26 | June 9 | September 27 | September 12 | 125 days | 4a |
| RhinelanderRhinelander Oneida County Airport | May 26 | June 8 | September 23 | September 5 | 120 days | 4b |
| Ladysmith3 mi W | May 27 | June 8 | September 22 | September 6 | 117 days | – |
| Port Wing | May 31 | June 13 | October 2 | September 17 | 123 days | – |
| Foxboro | June 1 | June 14 | September 22 | September 8 | 113 days | – |
| North Pelican | June 3 | June 27 | September 18 | September 1 | 106 days | – |
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities, growing-season length); station daily lows via ACIS (zone). Growing season: NOAA's median number of days between the last spring and first autumn 32°F night. Zone: the USDA's plant hardiness rule applied to the station's own 1991-2020 coldest nights.