Last frost dates in Wisconsin
204 NOAA weather stations in Wisconsin have thirty years of frost records. The median station sees its last 32 °F night around May 5; across the state that ranges from Apr 19 to Jun 3, so pick the station nearest you rather than a state-wide figure.
| KENOSHA | Apr 19 | May 3 | Apr 6 | Oct 26 | 189 |
| MILWAUKEE MITCHELL AP | Apr 19 | May 2 | Apr 6 | Oct 29 | 192 |
| RACINE | Apr 20 | May 6 | Apr 7 | Oct 24 | 184 |
| GENOA DAM 8 | Apr 22 | May 5 | Apr 6 | Oct 17 | 178 |
| SOUTH MILWAUKEE WWTP | Apr 22 | May 8 | Apr 9 | Oct 26 | 184 |
| STEUBEN 4 SE | Apr 22 | May 8 | Apr 7 | Oct 20 | 179 |
| GRAFTON WWTP | Apr 23 | May 9 | Apr 10 | Oct 24 | 182 |
| LA CROSSE MUNI AP | Apr 23 | May 6 | Apr 9 | Oct 17 | 177 |
| EAU CLAIRE 3SW | Apr 24 | May 7 | Apr 9 | Oct 14 | 170 |
| LYNXVILLE DAM 9 | Apr 24 | May 8 | Apr 9 | Oct 17 | 175 |
| OSHKOSH | Apr 24 | May 8 | Apr 10 | Oct 20 | 178 |
| RACINE BATTEN AP | Apr 24 | May 10 | Apr 11 | Oct 24 | 180 |
| ROCK SPRINGS 3 SW | Apr 24 | May 7 | Apr 10 | Oct 20 | 178 |
| JEFFERSON WWTP | Apr 25 | May 9 | Apr 12 | Oct 18 | 173 |
| LAKE GENEVA WWTP | Apr 25 | May 10 | Apr 10 | Oct 21 | 179 |
| SHEBOYGAN | Apr 25 | May 11 | Apr 11 | Oct 23 | 179 |
| AFTON - JANESVILLE WWTP | Apr 26 | May 11 | Apr 13 | Oct 15 | 170 |
| MT MARY COLLEGE | Apr 26 | May 12 | Apr 12 | Oct 18 | 173 |
| WEST ALLIS | Apr 26 | May 12 | Apr 12 | Oct 22 | 177 |
| CASHTON | Apr 27 | May 11 | Apr 14 | Oct 14 | 170 |
| FOND DU LAC 2 SW | Apr 27 | May 11 | Apr 13 | Oct 19 | 174 |
| LA CROSSE WFO | Apr 27 | May 12 | Apr 12 | Oct 13 | 167 |
| LANCASTER 4 WSW | Apr 27 | May 11 | Apr 11 | Oct 11 | 166 |
| MONROE WWTP | Apr 27 | May 12 | Apr 12 | Oct 14 | 170 |
| PORT WASHINGTON | Apr 27 | May 14 | Apr 11 | Oct 22 | 176 |
| TWO RIVERS | Apr 27 | May 10 | Apr 14 | Oct 21 | 175 |
| ALMA DAM 4 | Apr 28 | May 9 | Apr 13 | Oct 14 | 168 |
| CHARMANY FARM | Apr 28 | May 11 | Apr 14 | Oct 15 | 169 |
| DELAVAN WWTP | Apr 28 | May 14 | Apr 12 | Oct 14 | 168 |
| FT ATKINSON | Apr 28 | May 17 | Apr 14 | Oct 13 | 166 |
| HUSTISFORD WWTP | Apr 28 | May 13 | Apr 14 | Oct 10 | 164 |
| KENOSHA RGNL AP | Apr 28 | May 13 | Apr 13 | Oct 19 | 174 |
| PORTAGE WWTP | Apr 28 | May 12 | Apr 14 | Oct 10 | 164 |
| PRAIRIE DU CHIEN | Apr 28 | May 11 | Apr 14 | Oct 12 | 166 |
| WATERTOWN WWTP | Apr 28 | May 13 | Apr 14 | Oct 12 | 167 |
| BRODHEAD WWTP | Apr 29 | May 14 | Apr 14 | Oct 12 | 165 |
| LAKE MILLS WWTP | Apr 29 | May 13 | Apr 15 | Oct 14 | 167 |
| TREMPEALEAU DAM 6 | Apr 29 | May 13 | Apr 11 | Oct 11 | 165 |
| BROOKFIELD WWTP | Apr 30 | May 15 | Apr 16 | Oct 14 | 164 |
| CLINTON WWTP | Apr 30 | May 17 | Apr 15 | Oct 10 | 161 |
| GREEN BAY | Apr 30 | May 16 | Apr 16 | Oct 9 | 161 |
| JACKSON | Apr 30 | May 15 | Apr 15 | Oct 15 | 167 |
| LONE ROCK TRI CO AP | Apr 30 | May 14 | Apr 15 | Oct 9 | 161 |
| MANITOWOC | Apr 30 | May 15 | Apr 14 | Oct 20 | 171 |
| OCONOMOWOC WWTP | Apr 30 | May 17 | Apr 16 | Oct 12 | 164 |
| OSHKOSH WITTMAN AP | Apr 30 | May 13 | Apr 15 | Oct 13 | 165 |
| PADDOCK LAKE | Apr 30 | May 16 | Apr 15 | Oct 15 | 167 |
| PELL LAKE | Apr 30 | May 16 | Apr 16 | Oct 13 | 164 |
| PLATTEVILLE | Apr 30 | May 13 | Apr 14 | Oct 13 | 166 |
| RICHFIELD 3 SSW | Apr 30 | May 16 | Apr 16 | Oct 16 | 167 |
| STOUGHTON | Apr 30 | May 15 | Apr 16 | Oct 11 | 163 |
| WATERLOO WWTP | Apr 30 | May 15 | Apr 16 | Oct 9 | 163 |
| BELOIT | May 1 | May 16 | Apr 17 | Oct 12 | 162 |
| BERLIN WWTP | May 1 | May 16 | Apr 19 | Oct 8 | 158 |
| CHILTON | May 1 | May 17 | Apr 19 | Oct 14 | 162 |
| DURAND | May 1 | May 15 | Apr 17 | Oct 10 | 162 |
| FOND DU LAC CO AP | May 1 | May 17 | Apr 17 | Oct 10 | 160 |
| FOND DU LAC WWTP | May 1 | May 17 | Apr 18 | Oct 12 | 162 |
| GREEN BAY WFO | May 1 | May 16 | Apr 19 | Oct 11 | 160 |
| HORICON WWTP | May 1 | May 19 | Apr 16 | Oct 10 | 158 |
| JIM FALLS 3NW | May 1 | May 16 | Apr 17 | Oct 8 | 158 |
| KEWAUNEE | May 1 | May 17 | Apr 16 | Oct 18 | 168 |
| LODI | May 1 | May 15 | Apr 17 | Oct 10 | 162 |
| MADISON DANE RGNL AP | May 1 | May 16 | Apr 16 | Oct 10 | 160 |
| NECEDAH 5 WNW | May 1 | May 14 | Apr 17 | Oct 3 | 157 |
| RIPON 5 NE | May 1 | May 14 | Apr 16 | Oct 11 | 163 |
| TOWN OF WESTFORD | May 1 | May 16 | Apr 16 | Oct 11 | 163 |
| UW ARBORETUM - MADISON | May 1 | May 17 | Apr 18 | Oct 9 | 161 |
| W BEND PUBLIC WORKS | May 1 | May 18 | Apr 19 | Oct 12 | 161 |
| WAUKESHA WWTP | May 1 | May 18 | Apr 18 | Oct 13 | 162 |
| BEAVER DAM WWTP | May 2 | May 16 | Apr 19 | Oct 9 | 157 |
| MAUSTON 1 SE | May 2 | May 15 | Apr 19 | Oct 7 | 158 |
| REEDSBURG | May 2 | May 16 | Apr 18 | Oct 7 | 156 |
| SHEBOYGAN WWTP | May 2 | May 19 | Apr 17 | Oct 21 | 169 |
| WHITEWATER | May 2 | May 20 | Apr 18 | Oct 9 | 157 |
| BOSCOBEL AP | May 3 | May 18 | Apr 19 | Oct 7 | 155 |
| DARLINGTON WWTP | May 3 | May 19 | Apr 19 | Oct 4 | 153 |
| DODGEVILLE WWTP | May 3 | May 17 | Apr 19 | Oct 7 | 157 |
| GAYS MILLS | May 3 | May 18 | Apr 19 | Oct 7 | 156 |
| HALES CORNERS/WHITNALL PARK/BO | May 3 | May 19 | Apr 18 | Oct 14 | 162 |
| HINGHAM WWTP | May 3 | May 18 | Apr 18 | Oct 16 | 165 |
| MONTELLO | May 3 | May 18 | Apr 21 | Oct 5 | 153 |
| PLYMOUTH WWTP | May 3 | May 20 | Apr 19 | Oct 10 | 159 |
| SULLIVAN 3SE | May 3 | May 21 | Apr 18 | Oct 9 | 157 |
| APPLETON | May 4 | May 20 | Apr 21 | Oct 6 | 154 |
| ARLINGTON | May 4 | May 18 | Apr 20 | Oct 6 | 154 |
| CLINTONVILLE | May 4 | May 19 | Apr 22 | Oct 6 | 154 |
| MARINETTE | May 4 | May 20 | Apr 19 | Oct 11 | 160 |
| NEW LONDON | May 4 | May 19 | Apr 21 | Oct 6 | 153 |
| SAUK CITY WWTP | May 4 | May 18 | Apr 20 | Oct 6 | 155 |
| ST CROIX FALLS | May 4 | May 18 | Apr 20 | Oct 8 | 156 |
| STEVENS PT | May 4 | May 20 | Apr 22 | Oct 7 | 155 |
| WEST BEND | May 4 | May 21 | Apr 20 | Oct 11 | 157 |
| AMERY | May 5 | May 21 | Apr 20 | Oct 4 | 151 |
| BARABOO | May 5 | May 21 | Apr 21 | Oct 5 | 152 |
| BELGIUM WWTP | May 5 | May 22 | Apr 20 | Oct 12 | 159 |
| BLOOMER | May 5 | May 19 | Apr 23 | Oct 3 | 151 |
| BURLINGTON | May 5 | May 23 | Apr 21 | Oct 9 | 156 |
| CUMBERLAND | May 5 | May 18 | Apr 22 | Oct 4 | 152 |
| DODGE | May 5 | May 19 | Apr 21 | Oct 5 | 152 |
| HILLSBORO | May 5 | May 18 | Apr 22 | Oct 4 | 153 |
| HOLCOMBE | May 5 | May 21 | Apr 21 | Oct 2 | 149 |
| MARSHFIELD EXP FARM | May 5 | May 20 | Apr 22 | Oct 5 | 150 |
| MARSHFIELD MUNI AP | May 5 | May 20 | Apr 22 | Oct 5 | 152 |
| RICHLAND CTR | May 5 | May 19 | Apr 21 | Oct 6 | 154 |
| ROCHESTER WWTP | May 5 | May 23 | Apr 23 | Oct 10 | 156 |
| SAUKVILLE WWTP | May 5 | May 19 | Apr 22 | Oct 11 | 158 |
| SHEBOYGAN CO MEM AP | May 5 | May 21 | Apr 22 | Oct 8 | 154 |
| SLINGER WWTP | May 5 | May 20 | Apr 21 | Oct 5 | 152 |
| UNION GROVE | May 5 | May 20 | Apr 21 | Oct 8 | 156 |
| BALDWIN | May 6 | May 21 | Apr 21 | Oct 2 | 148 |
| BRILLION | May 6 | May 21 | Apr 22 | Oct 6 | 151 |
| CASHTON 3NNW | May 6 | May 20 | Apr 22 | Oct 3 | 150 |
| DALTON | May 6 | May 22 | Apr 22 | Oct 2 | 150 |
| DENMARK WWTP | May 6 | May 20 | Apr 22 | Oct 12 | 158 |
| FORESTVILLE-4E | May 6 | May 20 | Apr 22 | Oct 17 | 163 |
| GERMANTOWN | May 6 | May 25 | Apr 22 | Oct 8 | 154 |
| LUCK | May 6 | May 20 | Apr 23 | Oct 4 | 149 |
| MATHER 3 NW | May 6 | May 20 | Apr 24 | Oct 3 | 148 |
| ROSHOLT 9 NNE | May 6 | May 21 | Apr 24 | Oct 5 | 150 |
| SUPERIOR | May 6 | May 25 | Apr 24 | Oct 9 | 154 |
| WAUSAU DWTN AP | May 6 | May 21 | Apr 24 | Oct 4 | 150 |
| AUGUSTA RS | May 7 | May 20 | Apr 23 | Oct 1 | 146 |
| BIG FALLS HYDRO | May 7 | May 22 | Apr 25 | Oct 3 | 147 |
| GREEN BAY BOTANICAL | May 7 | May 22 | Apr 24 | Oct 9 | 154 |
| MAZOMANIE WWTP | May 7 | May 22 | Apr 22 | Oct 1 | 148 |
| STANLEY WWTP | May 7 | May 21 | Apr 24 | Oct 3 | 147 |
| VIROQUA | May 7 | May 21 | Apr 23 | Oct 2 | 148 |
| EAU CLAIRE RGNL AP | May 8 | May 21 | Apr 24 | Oct 4 | 149 |
| HARTFORD WWTP | May 8 | May 24 | Apr 24 | Oct 3 | 148 |
| MARKESAN | May 8 | May 23 | Apr 25 | Oct 2 | 144 |
| RICE LAKE | May 8 | May 23 | Apr 25 | Oct 2 | 145 |
| STURGEON BAY EXP FARM | May 8 | May 21 | Apr 25 | Oct 13 | 157 |
| WAUPACA | May 8 | May 21 | Apr 24 | Oct 6 | 151 |
| WISCONSIN DELLS | May 8 | May 22 | Apr 24 | Oct 3 | 146 |
| WISCONSIN RAPIDS ALEXANDER FLD | May 8 | May 22 | Apr 26 | Oct 1 | 145 |
| BLAIR | May 9 | May 23 | Apr 28 | Oct 1 | 143 |
| FRIENDSHIP | May 9 | May 23 | Apr 23 | Oct 3 | 147 |
| MENOMONIE | May 9 | May 24 | Apr 27 | Oct 1 | 143 |
| OCONTO 4 W | May 9 | May 23 | Apr 25 | Oct 6 | 150 |
| SHAWANO 2SSW | May 9 | May 24 | Apr 26 | Oct 2 | 144 |
| SPARTA | May 9 | May 22 | Apr 26 | Oct 1 | 144 |
| WEYERHAEUSER 1N | May 9 | May 27 | Apr 26 | Sep 29 | 140 |
| WISCONSIN RAPIDS | May 9 | May 24 | Apr 26 | Sep 30 | 142 |
| HANCOCK EXP FARM | May 10 | May 24 | Apr 25 | Oct 3 | 146 |
| MINONG 5 WSW | May 10 | May 26 | Apr 29 | Oct 4 | 144 |
| MONDOVI | May 10 | May 25 | Apr 27 | Oct 2 | 144 |
| NEILLSVILLE 3ESE | May 10 | May 25 | Apr 26 | Oct 1 | 144 |
| RICE RSVR TOMAHAWK-2 | May 10 | May 27 | Apr 28 | Oct 4 | 146 |
| RIDGELAND 1NNE | May 10 | May 26 | Apr 28 | Sep 29 | 140 |
| DANBURY | May 11 | May 28 | Apr 28 | Sep 30 | 138 |
| GRANTSBURG | May 11 | May 28 | Apr 27 | Oct 1 | 141 |
| MEDFORD | May 11 | May 26 | Apr 29 | Oct 1 | 141 |
| MERRILL | May 11 | May 27 | Apr 29 | Sep 30 | 139 |
| PESHTIGO | May 11 | May 26 | Apr 29 | Oct 5 | 145 |
| RIVER FALLS | May 11 | May 26 | Apr 26 | Oct 1 | 143 |
| HILLSBORO 2SW | May 12 | May 26 | Apr 28 | Sep 29 | 138 |
| SOLON SPRINGS | May 12 | May 27 | Apr 28 | Oct 2 | 142 |
| ELLSWORTH 1E | May 13 | May 27 | Apr 29 | Sep 29 | 139 |
| OWEN 1E | May 13 | May 29 | Apr 29 | Sep 26 | 136 |
| STOCKBRIDGE-MUNSEE RSVN | May 13 | May 26 | Apr 29 | Sep 30 | 141 |
| WILLOW RSVR | May 13 | May 27 | Apr 29 | Oct 3 | 141 |
| ANTIGO | May 14 | May 28 | Apr 30 | Sep 30 | 139 |
| EPHRAIM 1NE-WWTP | May 14 | May 28 | Apr 28 | Oct 18 | 155 |
| SPOONER AG RES STN | May 14 | May 29 | Apr 30 | Sep 28 | 135 |
| SURING | May 14 | May 29 | Apr 30 | Oct 1 | 139 |
| PARK FALLS DNR HQ | May 15 | May 30 | Apr 30 | Sep 28 | 134 |
| WASHINGTON IS | May 15 | May 31 | Apr 30 | Oct 14 | 152 |
| CLAM LAKE 4W | May 16 | May 27 | May 1 | Sep 30 | 136 |
| NECEDAH | May 17 | Jun 1 | May 2 | Sep 25 | 131 |
| PATTISON RANGER STAION | May 18 | Jun 3 | May 4 | Oct 3 | 135 |
| LAONA 6 SW | May 19 | Jun 2 | May 5 | Sep 29 | 131 |
| ST GERMAIN | May 19 | May 31 | May 5 | Oct 3 | 136 |
| WINTER | May 19 | Jun 3 | May 3 | Sep 27 | 129 |
| ASHLAND 3S | May 20 | Jun 3 | May 3 | Oct 2 | 133 |
| BAYFIELD 6 N | May 20 | Jun 5 | May 2 | Oct 8 | 141 |
| DRUMMOND | May 20 | Jun 2 | May 5 | Oct 1 | 132 |
| JUMP RVR 3E | May 20 | Jun 4 | May 3 | Sep 23 | 125 |
| MADELINE ISLAND | May 20 | Jun 3 | May 5 | Oct 9 | 140 |
| BUTTERNUT 3SW | May 22 | Jun 4 | May 6 | Sep 24 | 126 |
| GORDON | May 22 | Jun 4 | May 6 | Sep 26 | 126 |
| HAYWARD RS | May 22 | Jun 6 | May 2 | Sep 23 | 124 |
| LAKEWOOD 3 NE | May 22 | Jun 3 | May 7 | Sep 28 | 129 |
| RHINELANDER | May 22 | Jun 4 | May 6 | Sep 24 | 125 |
| ASHLAND KENNEDY MEM AP | May 23 | Jun 6 | May 8 | Sep 29 | 125 |
| BAYFIELD FISH HATCHERY | May 23 | Jun 5 | May 8 | Oct 2 | 131 |
| HAYWARD MUNI AP | May 23 | Jun 6 | May 5 | Sep 22 | 122 |
| MINOCQUA | May 23 | Jun 6 | May 7 | Sep 27 | 127 |
| PRENTICE #2 | May 23 | Jun 6 | May 6 | Sep 23 | 124 |
| RHINELANDER 4NE | May 23 | Jun 5 | May 7 | Sep 23 | 124 |
| SAXON 1WSW | May 23 | Jun 5 | May 4 | Oct 1 | 132 |
| BRULE RS | May 24 | Jun 6 | May 8 | Sep 26 | 124 |
| FLORENCE | May 24 | Jun 8 | May 9 | Sep 25 | 121 |
| GOODMAN SANITARY DIST | May 24 | Jun 7 | May 10 | Sep 30 | 128 |
| HURLEY | May 24 | Jun 7 | May 4 | Sep 28 | 128 |
| EAGLE RVR | May 25 | Jun 6 | May 10 | Sep 24 | 121 |
| REST LAKE | May 25 | Jun 9 | May 8 | Sep 21 | 117 |
| CRIVITZ HIGH FALLS | May 26 | Jun 11 | May 11 | Sep 22 | 118 |
| MELLEN 4 NE | May 26 | Jun 9 | May 8 | Sep 27 | 125 |
| RHINELANDER ONEIDA AP | May 26 | Jun 8 | May 9 | Sep 23 | 120 |
| LADYSMITH 3W | May 27 | Jun 8 | May 14 | Sep 22 | 117 |
| PORT WING | May 31 | Jun 13 | May 16 | Oct 2 | 123 |
| FOXBORO | Jun 1 | Jun 14 | May 18 | Sep 22 | 113 |
| NORTH PELICAN | Jun 3 | Jun 27 | May 20 | Sep 18 | 106 |
How to read the three dates
Average is the date by which, in half of the years between 1991 and 2020, the last 32 °F night had already happened. Safe is later: only one year in ten saw a frost after it, which is the date to set out frost-tender plants such as dahlia tubers and zinnia seedlings. Early is the risky end, with a frost after it in nine years out of ten.
Every figure is for the weather station, not for your garden. A valley bottom, a north slope or a spot near a lake can run a week or two either way. Cities are warmer than the countryside around them.
Where the numbers come from
The dates are NOAA's U.S. Climate Normals for 1991 to 2020, computed by the National Centers for Environmental Information for every station with thirty years of daily minimum temperatures. ZIP codes are matched to the nearest such station within 150 km using U.S. Census Bureau ZIP Code Tabulation Area centroids. Stations that never see a frost, such as much of south Florida, report no date and are left out.