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Home Garden Lot: Garden & Home Improvement

What Hardiness Zone Is Wisconsin?

USDA 2023 Plant Hardiness Zone Map · 872 ZIP codes · Data updated 2026-10-28

Quick answer

Wisconsin spans USDA hardiness zones 3b–6a on the 2023 Plant Hardiness Zone Map. The most common zone is 5b, covering 30% of Wisconsin's ZIP codes, followed by zone 5a (29%). Zone 5b means the coldest night of an average winter reaches −15°F to −10°F (−26°C to −23°C). Enter your ZIP code for your exact zone.

Wisconsin hardiness zones by share of ZIP codes

Zone 3b<1% · 1 ZIP
Zone 4a8% · 73 ZIPs
Zone 4b27% · 238 ZIPs
Zone 5a29% · 250 ZIPs
Zone 5b30% · 263 ZIPs
Zone 6a5% · 47 ZIPs

What the zones mean for Wisconsin gardeners

  • Coldest and warmest towns: among towns with NOAA weather stations, St Germain (1,643 ft) is in zone 4a, while Racine (595 ft) is in zone 6a. That is a difference of about 20°F in the coldest night of a typical winter.
  • Same zone, different frost dates: within zone 5b, the median last spring frost ranges from April 24 at Oshkosh to May 14 at Ephraim 1NE-WWTP, 20 days apart. Your zone tells you which perennials survive winter; your frost dates tell you when to plant.

Typical frost dates in each Wisconsin zone

Medians across NOAA weather stations in each zone. Colder zones usually have later spring frosts, but local terrain can shift the dates by weeks.

ZoneLast spring frostFirst fall frostStations
4aMay 19September 2824
4bMay 9October 151
5aMay 3October 755
5bMay 1October 1355
6aApril 23October 248

Hardiness zones for Wisconsin cities

Zones at the National Weather Service stations, mostly city airports, with their median frost dates.
Boscobel Airport5a−20°F to −15°F672May 3Oct 7
Eau Claire Regional Airport4b−25°F to −20°F885May 8Oct 4
Fond Du Lac County Airport5a−20°F to −15°F809May 1Oct 10
Grantsburg4a−30°F to −25°F990May 11Oct 1
Green Bay5b−15°F to −10°F682Apr 30Oct 9
Hayward Municipal Airport4a−30°F to −25°F1,204May 23Sep 22
Kenosha Regional Airport5b−15°F to −10°F743Apr 28Oct 19
La Crosse Municipal Airport5a−20°F to −15°F652Apr 23Oct 17
Lone Rock Tri County Airport5a−20°F to −15°F717Apr 30Oct 9
Madison Dane Regional Airport5b−15°F to −10°F866May 1Oct 10
Marshfield Municipal Airport4b−25°F to −20°F1,255May 5Oct 5
Milwaukee Mitchell Airport6a−10°F to −5°F670Apr 19Oct 29
Oshkosh Wittman Airport5b−15°F to −10°F782Apr 30Oct 13
Racine Batten Airport6a−10°F to −5°F674Apr 24Oct 24
Sheboygan County Memorial Airport5b−15°F to −10°F746May 5Oct 8
Wausau Dwtn Airport5a−20°F to −15°F1,181May 6Oct 4
Wisconsin Rapids Alexander Field4b−25°F to −20°F1,019May 8Oct 1

Hardiness zones for 194 towns in Wisconsin

Each NOAA weather station is shown with the USDA zone of the nearest ZIP code (within 8 miles). Coldest night is the zone's range for the average annual extreme minimum temperature. Click a column to sort.
Afton - Janesville Wwtp5b−15°F to −10°F762Apr 26Oct 15
Alma Dam 44b−25°F to −20°F670Apr 28Oct 14
Amery4b−25°F to −20°F1,070May 5Oct 4
Antigo4b−25°F to −20°F1,519May 14Sep 30
Appleton5b−15°F to −10°F792May 4Oct 6
Arlington5a−20°F to −15°F1,052May 4Oct 6
Ashland 3S5a−20°F to −15°F826May 20Oct 2
Augusta Ranger Station4b−25°F to −20°F960May 7Oct 1
Baldwin4b−25°F to −20°F1,100May 6Oct 2
Baraboo5a−20°F to −15°F823May 5Oct 5
Bayfield 6 N5a−20°F to −15°F820May 20Oct 8
Bayfield Fish Hatchery4b−25°F to −20°F615May 23Oct 2
Beaver Dam Wwtp5a−20°F to −15°F861May 2Oct 9
Belgium Wwtp5b−15°F to −10°F731May 5Oct 12
Beloit5b−15°F to −10°F788May 1Oct 12
Berlin Wwtp5a−20°F to −15°F766May 1Oct 8
Big Falls Hydro4a−30°F to −25°F1,205May 7Oct 3
Blair4b−25°F to −20°F855May 9Oct 1
Bloomer4b−25°F to −20°F990May 5Oct 3
Boscobel Airport5a−20°F to −15°F672May 3Oct 7
Brillion5b−15°F to −10°F810May 6Oct 6
Brodhead Wwtp5a−20°F to −15°F780Apr 29Oct 12
Brookfield Wwtp5b−15°F to −10°F830Apr 30Oct 14
Brule Ranger Station4a−30°F to −25°F1,000May 24Sep 26
Burlington5b−15°F to −10°F751May 5Oct 9
Butternut 3SW4a−30°F to −25°F1,570May 22Sep 24
Cashton5a−20°F to −15°F1,370Apr 27Oct 14
Cashton 3NNW5a−20°F to −15°F939May 6Oct 3
Charmany Farm5b−15°F to −10°F1,046Apr 28Oct 15
Chilton5b−15°F to −10°F840May 1Oct 14
Clam Lake 4W4a−30°F to −25°F1,498May 16Sep 30
Clinton Wwtp5b−15°F to −10°F924Apr 30Oct 10
Clintonville5a−20°F to −15°F802May 4Oct 6
Couderay 7 W4a−30°F to −25°F1,300Any monthAny month
Crivitz High Falls4b−25°F to −20°F950May 26Sep 22
Cumberland4b−25°F to −20°F1,240May 5Oct 4
Dalton5a−20°F to −15°F860May 6Oct 2
Darlington Wwtp5a−20°F to −15°F854May 3Oct 4
Delavan Wwtp5b−15°F to −10°F882Apr 28Oct 14
Denmark Wwtp5b−15°F to −10°F811May 6Oct 12
Dodge4b−25°F to −20°F685May 5Oct 5
Dodgeville Wwtp5a−20°F to −15°F1,118May 3Oct 7
Drummond4a−30°F to −25°F1,340May 20Oct 1
Durand4b−25°F to −20°F705May 1Oct 10
Eagle River4b−25°F to −20°F1,623May 25Sep 24
Eau Claire 3SW4b−25°F to −20°F880Apr 24Oct 14
Eau Claire Regional Airport4b−25°F to −20°F885May 8Oct 4
Ellsworth 1E4b−25°F to −20°F1,030May 13Sep 29
Ephraim 1NE-WWTP5b−15°F to −10°F733May 14Oct 18
Florence4b−25°F to −20°F1,300May 24Sep 25
Fond Du Lac 2 SW5b−15°F to −10°F772Apr 27Oct 19
Fond Du Lac County Airport5a−20°F to −15°F809May 1Oct 10
Fond Du Lac Wwtp5b−15°F to −10°F750May 1Oct 12
Forestville-4e5b−15°F to −10°F690May 6Oct 17
Fort Atkinson5b−15°F to −10°F800Apr 28Oct 13
Foxboro4a−30°F to −25°F932Jun 1Sep 22
Friendship4b−25°F to −20°F945May 9Oct 3
Gays Mills5a−20°F to −15°F689May 3Oct 7
Genoa Dam 85a−20°F to −15°F639Apr 22Oct 17
Germantown5b−15°F to −10°F850May 6Oct 8
Goodman Sanitary Dist4b−25°F to −20°F1,448May 24Sep 30
Gordon4a−30°F to −25°F1,040May 22Sep 26
Grafton Wwtp6a−10°F to −5°F741Apr 23Oct 24
Grantsburg4a−30°F to −25°F990May 11Oct 1
Green Bay5b−15°F to −10°F682Apr 30Oct 9
Green Bay Botanical5b−15°F to −10°F694May 7Oct 9
Green Bay WFO5b−15°F to −10°F682May 1Oct 11
Hales Corners/whitnall Park/bo5b−15°F to −10°F774May 3Oct 14
Hancock Experiment Farm4b−25°F to −20°F1,092May 10Oct 3
Hartford Wwtp5a−20°F to −15°F961May 8Oct 3
Hayward Municipal Airport4a−30°F to −25°F1,204May 23Sep 22
Hillsboro4b−25°F to −20°F940May 5Oct 4
Hillsboro 2SW4b−25°F to −20°F1,043May 12Sep 29
Hingham Wwtp5b−15°F to −10°F763May 3Oct 16
Holcombe4b−25°F to −20°F1,057May 5Oct 2
Horicon Wwtp5a−20°F to −15°F881May 1Oct 10
Hurley4b−25°F to −20°F1,444May 24Sep 28
Hustisford Wwtp5a−20°F to −15°F864Apr 28Oct 10
Jackson5b−15°F to −10°F903Apr 30Oct 15
Jefferson Wwtp5b−15°F to −10°F783Apr 25Oct 18
Jim Falls 3NW4b−25°F to −20°F1,070May 1Oct 8
Jump River 3E4a−30°F to −25°F1,265May 20Sep 23
Kenosha6a−10°F to −5°F600Apr 19Oct 26
Kenosha Regional Airport5b−15°F to −10°F743Apr 28Oct 19
Kewaunee5b−15°F to −10°F593May 1Oct 18
La Crosse Municipal Airport5a−20°F to −15°F652Apr 23Oct 17
La Crosse WFO5a−20°F to −15°F1,307Apr 27Oct 13
Ladysmith 3W4a−30°F to −25°F1,130May 27Sep 22
Lake Geneva Wwtp5b−15°F to −10°F846Apr 25Oct 21
Lake Mills Wwtp5b−15°F to −10°F811Apr 29Oct 14
Lakewood 3 NE4b−25°F to −20°F1,196May 22Sep 28
Lancaster 4 WSW5a−20°F to −15°F1,040Apr 27Oct 11
Laona 6 SW4b−25°F to −20°F1,695May 19Sep 29
Lodi5a−20°F to −15°F824May 1Oct 10
Lone Rock Tri County Airport5a−20°F to −15°F717Apr 30Oct 9
Luck4b−25°F to −20°F1,220May 6Oct 4
Lynxville Dam 95a−20°F to −15°F633Apr 24Oct 17
Madison Dane Regional Airport5b−15°F to −10°F866May 1Oct 10
Manitowoc5b−15°F to −10°F584Apr 30Oct 20
Markesan5a−20°F to −15°F861May 8Oct 2
Marshfield Experiment Farm4b−25°F to −20°F1,237May 5Oct 5
Marshfield Municipal Airport4b−25°F to −20°F1,255May 5Oct 5
Mather 3 NW4b−25°F to −20°F978May 6Oct 3
Mauston 1 SE5a−20°F to −15°F865May 2Oct 7
Mazomanie Wwtp5a−20°F to −15°F764May 7Oct 1
Medford4a−30°F to −25°F1,470May 11Oct 1
Mellen 4 NE4b−25°F to −20°F1,300May 26Sep 27
Menomonie4b−25°F to −20°F780May 9Oct 1
Merrill4b−25°F to −20°F1,250May 11Sep 30
Milwaukee Mitchell Airport6a−10°F to −5°F670Apr 19Oct 29
Minocqua4a−30°F to −25°F1,601May 23Sep 27
Minong 5 WSW4a−30°F to −25°F1,075May 10Oct 4
Mondovi4b−25°F to −20°F830May 10Oct 2
Monroe Wwtp5a−20°F to −15°F991Apr 27Oct 14
Montello5a−20°F to −15°F786May 3Oct 5
Mount Mary College5b−15°F to −10°F715Apr 26Oct 18
Necedah4b−25°F to −20°F922May 17Sep 25
Neillsville 3ESE4b−25°F to −20°F1,080May 10Oct 1
New London5a−20°F to −15°F800May 4Oct 6
Oconomowoc Wwtp5b−15°F to −10°F858Apr 30Oct 12
Oconto 4 W5a−20°F to −15°F660May 9Oct 6
Oshkosh5b−15°F to −10°F750Apr 24Oct 20
Oshkosh Wittman Airport5b−15°F to −10°F782Apr 30Oct 13
Owen 1E4b−25°F to −20°F1,238May 13Sep 26
Paddock Lake5b−15°F to −10°F775Apr 30Oct 15
Park Falls Dnr HQ4a−30°F to −25°F1,525May 15Sep 28
Pattison Ranger Staion4b−25°F to −20°F1,100May 18Oct 3
Pell Lake5b−15°F to −10°F840Apr 30Oct 13
Peshtigo5b−15°F to −10°F600May 11Oct 5
Platteville5a−20°F to −15°F990Apr 30Oct 13
Plymouth Wwtp5b−15°F to −10°F828May 3Oct 10
Port Washington5b−15°F to −10°F594Apr 27Oct 22
Port Wing5a−20°F to −15°F651May 31Oct 2
Portage Wwtp5a−20°F to −15°F785Apr 28Oct 10
Prairie Du Chien5a−20°F to −15°F658Apr 28Oct 12
Prentice #24a−30°F to −25°F1,540May 23Sep 23
Racine6a−10°F to −5°F595Apr 20Oct 24
Racine Batten Airport6a−10°F to −5°F674Apr 24Oct 24
Reedsburg5a−20°F to −15°F926May 2Oct 7
Rest Lake4a−30°F to −25°F1,612May 25Sep 21
Rhinelander 4NE4b−25°F to −20°F1,586May 23Sep 23
Rice Lake4b−25°F to −20°F1,103May 8Oct 2
Rice Rsvr Tomahawk-24a−30°F to −25°F1,460May 10Oct 4
Richfield 3 SSW5a−20°F to −15°F984Apr 30Oct 16
Richland Center5a−20°F to −15°F728May 5Oct 6
Ridgeland 1NNE4b−25°F to −20°F1,080May 10Sep 29
Ripon 5 NE5a−20°F to −15°F930May 1Oct 11
River Falls4b−25°F to −20°F940May 11Oct 1
Rochester Wwtp5b−15°F to −10°F783May 5Oct 10
Rock Springs 3 SW5a−20°F to −15°F1,260Apr 24Oct 20
Rosholt 9 NNE4b−25°F to −20°F1,183May 6Oct 5
Sauk City Wwtp5a−20°F to −15°F750May 4Oct 6
Saukville Wwtp5b−15°F to −10°F766May 5Oct 11
Saxon 1WSW4b−25°F to −20°F1,165May 23Oct 1
Shawano 2SSW5a−20°F to −15°F806May 9Oct 2
Sheboygan5b−15°F to −10°F648Apr 25Oct 23
Sheboygan County Memorial Airport5b−15°F to −10°F746May 5Oct 8
Sheboygan Wwtp6a−10°F to −5°F603May 2Oct 21
Slinger Wwtp5a−20°F to −15°F1,029May 5Oct 5
Solon Springs4a−30°F to −25°F1,130May 12Oct 2
South Milwaukee Wwtp6a−10°F to −5°F650Apr 22Oct 26
Sparta4b−25°F to −20°F782May 9Oct 1
Spooner Agricultural Reservoir Station4a−30°F to −25°F1,100May 14Sep 28
St Croix Falls4b−25°F to −20°F750May 4Oct 8
St Germain4a−30°F to −25°F1,643May 19Oct 3
Stanley Wwtp4b−25°F to −20°F1,080May 7Oct 3
Steuben 4 SE5a−20°F to −15°F1,015Apr 22Oct 20
Stevens Point5a−20°F to −15°F1,079May 4Oct 7
Stockbridge-munsee Rsvn4b−25°F to −20°F1,050May 13Sep 30
Stoughton5b−15°F to −10°F840Apr 30Oct 11
Sturgeon Bay Experiment Farm5b−15°F to −10°F699May 8Oct 13
Sullivan 3SE5b−15°F to −10°F933May 3Oct 9
Suring5a−20°F to −15°F792May 14Oct 1
Town Of Westford5a−20°F to −15°F879May 1Oct 11
Trempealeau Dam 65a−20°F to −15°F660Apr 29Oct 11
Two Rivers5b−15°F to −10°F589Apr 27Oct 21
Union Grove5b−15°F to −10°F730May 5Oct 8
Uw Arboretum - Madison5a−20°F to −15°F870May 1Oct 9
Viroqua5a−20°F to −15°F1,255May 7Oct 2
W Bend Public Works5b−15°F to −10°F980May 1Oct 12
Washington Island6a−10°F to −5°F686May 15Oct 14
Waterloo Wwtp5b−15°F to −10°F800Apr 30Oct 9
Watertown Wwtp5b−15°F to −10°F825Apr 28Oct 12
Waukesha Wwtp5b−15°F to −10°F789May 1Oct 13
Waupaca5a−20°F to −15°F837May 8Oct 6
Wausau Dwtn Airport5a−20°F to −15°F1,181May 6Oct 4
West Allis5b−15°F to −10°F723Apr 26Oct 22
Weyerhaeuser 1N4a−30°F to −25°F1,195May 9Sep 29
Whitewater5b−15°F to −10°F875May 2Oct 9
Willow Rsvr4a−30°F to −25°F1,532May 13Oct 3
Winter4a−30°F to −25°F1,355May 19Sep 27
Wisconsin Dells5a−20°F to −15°F835May 8Oct 3
Wisconsin Rapids4b−25°F to −20°F1,033May 9Sep 30
Wisconsin Rapids Alexander Field4b−25°F to −20°F1,019May 8Oct 1

Frequently asked questions

What hardiness zone is Wisconsin?

Wisconsin is in USDA hardiness zones 3b–6a on the 2023 USDA Plant Hardiness Zone Map. Zone 5b is the most common, covering 30% of Wisconsin's ZIP codes, and zone 5a covers 29%. Enter your ZIP code for your exact zone.

What does zone 5b mean?

Zone 5b means the average annual extreme minimum temperature, the coldest night of a typical winter, is −15°F to −10°F (−26°C to −23°C). Perennials, shrubs and trees rated for zone 5b or colder should survive winter there.

What is the coldest hardiness zone in Wisconsin?

Zone 3b is the coldest zone mapped in Wisconsin, and zone 6a is the warmest, found around Racine.

Did Wisconsin's hardiness zones change in 2023?

The USDA released a new Plant Hardiness Zone Map in November 2023, based on 1991–2020 temperatures instead of 1976–2005. About half of the United States shifted half a zone warmer. Check your ZIP code here, because plant tags and older books may still list your 2012 zone.

When should I plant in zone 5b?

Hardiness zones don't set planting dates; frost dates do. Inside zone 5b in Wisconsin, the median last spring frost varies from April 24 to May 14. Look up your local frost dates and plant tender crops such as tomatoes after the 10%-risk last-frost date.

Zone and frost dates: use both

Your hardiness zone answers one question: will this plant survive the winter here? Choose perennials, shrubs, trees and bulbs rated for your zone or a colder one. For vegetables and annuals, what matters is the length of the frost-free season. See Wisconsin frost dates by town, or get a planting calendar for your ZIP code with start-indoors, transplant and sowing dates for 30 crops.

Sources and method

Zones are from the USDA 2023 Plant Hardiness Zone Map ZIP-code files published by the PRISM Climate Group, Oregon State University, based on 1991–2020 minimum temperatures. ZIP codes are assigned to states by USPS prefix. Town zones use the ZIP code nearest each NOAA 1991–2020 Climate Normals station. This is an independent tool, not an official USDA site. Full methodology.

Hardiness zones in other states