Wisconsin Frost Dates: Last and First Frost by Town

205 NOAA weather stations · 1991–2020 U.S. Climate Normals · Data updated 2026-10-29

Quick answer

Across Wisconsin's 204 NOAA stations with regular frost, the median last spring frost is May 5 and the median first fall frost is October 6. Last frost dates range from April 19 at Kenosha to June 3 at North Pelican, so enter your ZIP code below for the station nearest you.

How frost dates vary across Wisconsin

North vs south: stations in the northern third of the state (north of 44.9°N) reach their median last frost about 17 days later than the southern third (south of 43.5°N).
Safety margin: the median 10%-risk date (May 20) is about 15 days after the median last frost. Waiting until then cuts the chance of a killing frost on tender transplants from 1 in 2 to 1 in 10.

Frost dates at Wisconsin's major weather stations

These National Weather Service stations, mostly at airports, have the longest and most complete records in the state.


Ashland Kennedy Memorial Airport	826	May 23	Jun 6	Sep 29	125
Boscobel Airport	672	May 3	May 18	Oct 7	155
Eau Claire Regional Airport	885	May 8	May 21	Oct 4	149
Fond Du Lac County Airport	809	May 1	May 17	Oct 10	160
Grantsburg	990	May 11	May 28	Oct 1	141
Green Bay	682	Apr 30	May 16	Oct 9	161
Hayward Municipal Airport	1,204	May 23	Jun 6	Sep 22	122
Kenosha Regional Airport	743	Apr 28	May 13	Oct 19	174
La Crosse Municipal Airport	652	Apr 23	May 6	Oct 17	177
Lone Rock Tri County Airport	717	Apr 30	May 14	Oct 9	161
Madison Dane Regional Airport	866	May 1	May 16	Oct 10	160
Marshfield Municipal Airport	1,255	May 5	May 20	Oct 5	152
Milwaukee Mitchell Airport	670	Apr 19	May 2	Oct 29	192
Necedah 5 WNW	933	May 1	May 14	Oct 3	157
Oshkosh Wittman Airport	782	Apr 30	May 13	Oct 13	165
Racine Batten Airport	674	Apr 24	May 10	Oct 24	180
Rhinelander Oneida Airport	1,599	May 26	Jun 8	Sep 23	120
Sheboygan County Memorial Airport	746	May 5	May 21	Oct 8	154
Wausau Dwtn Airport	1,181	May 6	May 21	Oct 4	150
Wisconsin Rapids Alexander Field	1,019	May 8	May 22	Oct 1	145

All 205 stations in Wisconsin

Last frost and first frost are medians: a 50% chance of a 32°F night after (spring) or before (fall) that date. 10% risk is the spring date with only a 1-in-10 chance of a later frost. Click a column to sort.

Filter by station name


Afton - Janesville Wwtp	762	Apr 26	May 11	Oct 15	170
Alma Dam 4	670	Apr 28	May 9	Oct 14	168
Amery	1,070	May 5	May 21	Oct 4	151
Antigo	1,519	May 14	May 28	Sep 30	139
Appleton	792	May 4	May 20	Oct 6	154
Arlington	1,052	May 4	May 18	Oct 6	154
Ashland 3S	826	May 20	Jun 3	Oct 2	133
Ashland Kennedy Memorial Airport	826	May 23	Jun 6	Sep 29	125
Augusta Ranger Station	960	May 7	May 20	Oct 1	146
Baldwin	1,100	May 6	May 21	Oct 2	148
Baraboo	823	May 5	May 21	Oct 5	152
Bayfield 6 N	820	May 20	Jun 5	Oct 8	141
Bayfield Fish Hatchery	615	May 23	Jun 5	Oct 2	131
Beaver Dam Wwtp	861	May 2	May 16	Oct 9	157
Belgium Wwtp	731	May 5	May 22	Oct 12	159
Beloit	788	May 1	May 16	Oct 12	162
Berlin Wwtp	766	May 1	May 16	Oct 8	158
Big Falls Hydro	1,205	May 7	May 22	Oct 3	147
Blair	855	May 9	May 23	Oct 1	143
Bloomer	990	May 5	May 19	Oct 3	151
Boscobel Airport	672	May 3	May 18	Oct 7	155
Brillion	810	May 6	May 21	Oct 6	151
Brodhead Wwtp	780	Apr 29	May 14	Oct 12	165
Brookfield Wwtp	830	Apr 30	May 15	Oct 14	164
Brule Ranger Station	1,000	May 24	Jun 6	Sep 26	124
Burlington	751	May 5	May 23	Oct 9	156
Butternut 3SW	1,570	May 22	Jun 4	Sep 24	126
Cashton	1,370	Apr 27	May 11	Oct 14	170
Cashton 3NNW	939	May 6	May 20	Oct 3	150
Charmany Farm	1,046	Apr 28	May 11	Oct 15	169
Chilton	840	May 1	May 17	Oct 14	162
Clam Lake 4W	1,498	May 16	May 27	Sep 30	136
Clinton Wwtp	924	Apr 30	May 17	Oct 10	161
Clintonville	802	May 4	May 19	Oct 6	154
Couderay 7 W	1,300	Any month	Any month	Any month	100
Crivitz High Falls	950	May 26	Jun 11	Sep 22	118
Cumberland	1,240	May 5	May 18	Oct 4	152
Dalton	860	May 6	May 22	Oct 2	150
Danbury	950	May 11	May 28	Sep 30	138
Darlington Wwtp	854	May 3	May 19	Oct 4	153
Delavan Wwtp	882	Apr 28	May 14	Oct 14	168
Denmark Wwtp	811	May 6	May 20	Oct 12	158
Dodge	685	May 5	May 19	Oct 5	152
Dodgeville Wwtp	1,118	May 3	May 17	Oct 7	157
Drummond	1,340	May 20	Jun 2	Oct 1	132
Durand	705	May 1	May 15	Oct 10	162
Eagle River	1,623	May 25	Jun 6	Sep 24	121
Eau Claire 3SW	880	Apr 24	May 7	Oct 14	170
Eau Claire Regional Airport	885	May 8	May 21	Oct 4	149
Ellsworth 1E	1,030	May 13	May 27	Sep 29	139
Ephraim 1NE-WWTP	733	May 14	May 28	Oct 18	155
Florence	1,300	May 24	Jun 8	Sep 25	121
Fond Du Lac 2 SW	772	Apr 27	May 11	Oct 19	174
Fond Du Lac County Airport	809	May 1	May 17	Oct 10	160
Fond Du Lac Wwtp	750	May 1	May 17	Oct 12	162
Forestville-4e	690	May 6	May 20	Oct 17	163
Fort Atkinson	800	Apr 28	May 17	Oct 13	166
Foxboro	932	Jun 1	Jun 14	Sep 22	113
Friendship	945	May 9	May 23	Oct 3	147
Gays Mills	689	May 3	May 18	Oct 7	156
Genoa Dam 8	639	Apr 22	May 5	Oct 17	178
Germantown	850	May 6	May 25	Oct 8	154
Goodman Sanitary Dist	1,448	May 24	Jun 7	Sep 30	128
Gordon	1,040	May 22	Jun 4	Sep 26	126
Grafton Wwtp	741	Apr 23	May 9	Oct 24	182
Grantsburg	990	May 11	May 28	Oct 1	141
Green Bay	682	Apr 30	May 16	Oct 9	161
Green Bay Botanical	694	May 7	May 22	Oct 9	154
Green Bay WFO	682	May 1	May 16	Oct 11	160
Hales Corners/whitnall Park/bo	774	May 3	May 19	Oct 14	162
Hancock Experiment Farm	1,092	May 10	May 24	Oct 3	146
Hartford Wwtp	961	May 8	May 24	Oct 3	148
Hayward Municipal Airport	1,204	May 23	Jun 6	Sep 22	122
Hayward Ranger Station	1,200	May 22	Jun 6	Sep 23	124
Hillsboro	940	May 5	May 18	Oct 4	153
Hillsboro 2SW	1,043	May 12	May 26	Sep 29	138
Hingham Wwtp	763	May 3	May 18	Oct 16	165
Holcombe	1,057	May 5	May 21	Oct 2	149
Horicon Wwtp	881	May 1	May 19	Oct 10	158
Hurley	1,444	May 24	Jun 7	Sep 28	128
Hustisford Wwtp	864	Apr 28	May 13	Oct 10	164
Jackson	903	Apr 30	May 15	Oct 15	167
Jefferson Wwtp	783	Apr 25	May 9	Oct 18	173
Jim Falls 3NW	1,070	May 1	May 16	Oct 8	158
Jump River 3E	1,265	May 20	Jun 4	Sep 23	125
Kenosha	600	Apr 19	May 3	Oct 26	189
Kenosha Regional Airport	743	Apr 28	May 13	Oct 19	174
Kewaunee	593	May 1	May 17	Oct 18	168
La Crosse Municipal Airport	652	Apr 23	May 6	Oct 17	177
La Crosse WFO	1,307	Apr 27	May 12	Oct 13	167
Ladysmith 3W	1,130	May 27	Jun 8	Sep 22	117
Lake Geneva Wwtp	846	Apr 25	May 10	Oct 21	179
Lake Mills Wwtp	811	Apr 29	May 13	Oct 14	167
Lakewood 3 NE	1,196	May 22	Jun 3	Sep 28	129
Lancaster 4 WSW	1,040	Apr 27	May 11	Oct 11	166
Laona 6 SW	1,695	May 19	Jun 2	Sep 29	131
Lodi	824	May 1	May 15	Oct 10	162
Lone Rock Tri County Airport	717	Apr 30	May 14	Oct 9	161
Luck	1,220	May 6	May 20	Oct 4	149
Lynxville Dam 9	633	Apr 24	May 8	Oct 17	175
Madeline Island	660	May 20	Jun 3	Oct 9	140
Madison Dane Regional Airport	866	May 1	May 16	Oct 10	160
Manitowoc	584	Apr 30	May 15	Oct 20	171
Marinette	589	May 4	May 20	Oct 11	160
Markesan	861	May 8	May 23	Oct 2	144
Marshfield Experiment Farm	1,237	May 5	May 20	Oct 5	150
Marshfield Municipal Airport	1,255	May 5	May 20	Oct 5	152
Mather 3 NW	978	May 6	May 20	Oct 3	148
Mauston 1 SE	865	May 2	May 15	Oct 7	158
Mazomanie Wwtp	764	May 7	May 22	Oct 1	148
Medford	1,470	May 11	May 26	Oct 1	141
Mellen 4 NE	1,300	May 26	Jun 9	Sep 27	125
Menomonie	780	May 9	May 24	Oct 1	143
Merrill	1,250	May 11	May 27	Sep 30	139
Milwaukee Mitchell Airport	670	Apr 19	May 2	Oct 29	192
Minocqua	1,601	May 23	Jun 6	Sep 27	127
Minong 5 WSW	1,075	May 10	May 26	Oct 4	144
Mondovi	830	May 10	May 25	Oct 2	144
Monroe Wwtp	991	Apr 27	May 12	Oct 14	170
Montello	786	May 3	May 18	Oct 5	153
Mount Mary College	715	Apr 26	May 12	Oct 18	173
Necedah	922	May 17	Jun 1	Sep 25	131
Necedah 5 WNW	933	May 1	May 14	Oct 3	157
Neillsville 3ESE	1,080	May 10	May 25	Oct 1	144
New London	800	May 4	May 19	Oct 6	153
North Pelican	1,610	Jun 3	Jun 27	Sep 18	106
Oconomowoc Wwtp	858	Apr 30	May 17	Oct 12	164
Oconto 4 W	660	May 9	May 23	Oct 6	150
Oshkosh	750	Apr 24	May 8	Oct 20	178
Oshkosh Wittman Airport	782	Apr 30	May 13	Oct 13	165
Owen 1E	1,238	May 13	May 29	Sep 26	136
Paddock Lake	775	Apr 30	May 16	Oct 15	167
Park Falls Dnr HQ	1,525	May 15	May 30	Sep 28	134
Pattison Ranger Staion	1,100	May 18	Jun 3	Oct 3	135
Pell Lake	840	Apr 30	May 16	Oct 13	164
Peshtigo	600	May 11	May 26	Oct 5	145
Platteville	990	Apr 30	May 13	Oct 13	166
Plymouth Wwtp	828	May 3	May 20	Oct 10	159
Port Washington	594	Apr 27	May 14	Oct 22	176
Port Wing	651	May 31	Jun 13	Oct 2	123
Portage Wwtp	785	Apr 28	May 12	Oct 10	164
Prairie Du Chien	658	Apr 28	May 11	Oct 12	166
Prentice #2	1,540	May 23	Jun 6	Sep 23	124
Racine	595	Apr 20	May 6	Oct 24	184
Racine Batten Airport	674	Apr 24	May 10	Oct 24	180
Reedsburg	926	May 2	May 16	Oct 7	156
Rest Lake	1,612	May 25	Jun 9	Sep 21	117
Rhinelander	1,572	May 22	Jun 4	Sep 24	125
Rhinelander 4NE	1,586	May 23	Jun 5	Sep 23	124
Rhinelander Oneida Airport	1,599	May 26	Jun 8	Sep 23	120
Rice Lake	1,103	May 8	May 23	Oct 2	145
Rice Rsvr Tomahawk-2	1,460	May 10	May 27	Oct 4	146
Richfield 3 SSW	984	Apr 30	May 16	Oct 16	167
Richland Center	728	May 5	May 19	Oct 6	154
Ridgeland 1NNE	1,080	May 10	May 26	Sep 29	140
Ripon 5 NE	930	May 1	May 14	Oct 11	163
River Falls	940	May 11	May 26	Oct 1	143
Rochester Wwtp	783	May 5	May 23	Oct 10	156
Rock Springs 3 SW	1,260	Apr 24	May 7	Oct 20	178
Rosholt 9 NNE	1,183	May 6	May 21	Oct 5	150
Sauk City Wwtp	750	May 4	May 18	Oct 6	155
Saukville Wwtp	766	May 5	May 19	Oct 11	158
Saxon 1WSW	1,165	May 23	Jun 5	Oct 1	132
Shawano 2SSW	806	May 9	May 24	Oct 2	144
Sheboygan	648	Apr 25	May 11	Oct 23	179
Sheboygan County Memorial Airport	746	May 5	May 21	Oct 8	154
Sheboygan Wwtp	603	May 2	May 19	Oct 21	169
Slinger Wwtp	1,029	May 5	May 20	Oct 5	152
Solon Springs	1,130	May 12	May 27	Oct 2	142
South Milwaukee Wwtp	650	Apr 22	May 8	Oct 26	184
Sparta	782	May 9	May 22	Oct 1	144
Spooner Agricultural Reservoir Station	1,100	May 14	May 29	Sep 28	135
St Croix Falls	750	May 4	May 18	Oct 8	156
St Germain	1,643	May 19	May 31	Oct 3	136
Stanley Wwtp	1,080	May 7	May 21	Oct 3	147
Steuben 4 SE	1,015	Apr 22	May 8	Oct 20	179
Stevens Point	1,079	May 4	May 20	Oct 7	155
Stockbridge-munsee Rsvn	1,050	May 13	May 26	Sep 30	141
Stoughton	840	Apr 30	May 15	Oct 11	163
Sturgeon Bay Experiment Farm	699	May 8	May 21	Oct 13	157
Sullivan 3SE	933	May 3	May 21	Oct 9	157
Superior	607	May 6	May 25	Oct 9	154
Suring	792	May 14	May 29	Oct 1	139
Town Of Westford	879	May 1	May 16	Oct 11	163
Trempealeau Dam 6	660	Apr 29	May 13	Oct 11	165
Two Rivers	589	Apr 27	May 10	Oct 21	175
Union Grove	730	May 5	May 20	Oct 8	156
Uw Arboretum - Madison	870	May 1	May 17	Oct 9	161
Viroqua	1,255	May 7	May 21	Oct 2	148
W Bend Public Works	980	May 1	May 18	Oct 12	161
Washington Island	686	May 15	May 31	Oct 14	152
Waterloo Wwtp	800	Apr 30	May 15	Oct 9	163
Watertown Wwtp	825	Apr 28	May 13	Oct 12	167
Waukesha Wwtp	789	May 1	May 18	Oct 13	162
Waupaca	837	May 8	May 21	Oct 6	151
Wausau Dwtn Airport	1,181	May 6	May 21	Oct 4	150
West Allis	723	Apr 26	May 12	Oct 22	177
West Bend	940	May 4	May 21	Oct 11	157
Weyerhaeuser 1N	1,195	May 9	May 27	Sep 29	140
Whitewater	875	May 2	May 20	Oct 9	157
Willow Rsvr	1,532	May 13	May 27	Oct 3	141
Winter	1,355	May 19	Jun 3	Sep 27	129
Wisconsin Dells	835	May 8	May 22	Oct 3	146
Wisconsin Rapids	1,033	May 9	May 24	Sep 30	142
Wisconsin Rapids Alexander Field	1,019	May 8	May 22	Oct 1	145

Frequently asked questions

When is the last frost in Wisconsin?

The median last spring frost (32°F) across Wisconsin's NOAA weather stations is May 5, based on 1991–2020 climate normals. It ranges from April 19 at Kenosha to June 3 at North Pelican. For a safer planting date, use the 10%-risk date; the state median for that is May 20.

When is the first frost in Wisconsin?

The median first fall frost across Wisconsin's stations is October 6. The earliest median first frost is September 18 at North Pelican, and the latest is October 29 at Milwaukee Mitchell Airport.

How long is the growing season in Wisconsin?

The median frost-free season is 154 days across Wisconsin's stations, from 106 days at North Pelican to 192 days at Milwaukee Mitchell Airport.

When should I plant tomatoes in Wisconsin?

Plant tomatoes outdoors after your local last frost, ideally after the 10%-risk date when nights stay above 50°F. At a typical Wisconsin station that means starting seeds indoors 6–8 weeks before May 5 and transplanting from about May 20. Check your ZIP code, because dates vary by weeks across the state.

Can it frost in summer in Wisconsin?

Yes, at 1 station in Wisconsin a 32°F night is possible in any month, mostly at high elevation or far north. There is no reliable frost-free season there; use cold-hardy crops and row covers.

How to use these dates

Frost dates are 30-year averages from NOAA, not forecasts. Use them to plan seed starting and planting, then watch the 10-day forecast as the date approaches. Cold air settles in valleys and low spots, so a garden at the bottom of a slope can frost a week or more later in spring than the nearest station shows.

Ready to plan? The planting calendar by ZIP code turns these dates into start-indoors, transplant and sowing dates for 30 crops.

Sources and method

Dates are the 32°F freeze probabilities published in the NOAA NCEI 1991–2020 U.S. Climate Normals for each station. Station names are NOAA's, lightly expanded for readability. See the methodology or download the full table.