USDA zone 5b in Wisconsin
USDA plant hardiness zone 5b covers 52 locations across Wisconsin (average annual extreme minimum −15 to −10 °F): Bayfield, WI, Beloit, WI, Caledonia, WI, Chilton, WI, Cottage Grove, WI, Delavan, WI, and 46 more. Average last spring frost across this group ranges April 19 (Milwaukee) to May 20 (Bayfield), and growing seasons run 140–192 days (Bayfield to Milwaukee) — even within one state, because hardiness sets winter survival, not planting dates. The table below gives every Wisconsin location's own frost dates; the printable planting calendar uses New Berlin, this group's median-season location.
- USDA zone
- 5b−15 to −10 °F
- Last frost range
- Apr 19–May 20avg, 32°F
- First frost range
- Oct 6–Oct 29avg, 32°F
- Growing season range
- 140–192days
Locations in this group
Every location below shares this zone and a nearby weather station, but keeps its own frost dates — find your town for its own numbers, or use the ZIP planner on the home page for an instant personalized answer.
| Location | Also covers | Nearest station | Last frost | First frost | Season (days) |
|---|---|---|---|---|---|
| Bayfield | — | Madeline Island | May 20 | Oct 9 | 140 |
| Beloit | Loves Park, Roscoe, Poplar Grove, Rockton, South Beloit, Caledonia, +1 more | Beloit | May 1 | Oct 12 | 162 |
| Caledonia | Mount Pleasant | Racine Batten Ap | Apr 24 | Oct 24 | 180 |
| Chilton | Stockbridge, Kiel, New Holstein, St. Nazianz | Chilton | May 1 | Oct 14 | 162 |
| Cottage Grove | Monona, Maple Bluff | Madison Dane Rgnl Ap | May 1 | Oct 10 | 160 |
| Delavan | — | Delavan Wwtp | Apr 28 | Oct 14 | 168 |
| Denmark | — | Denmark Wwtp | May 6 | Oct 12 | 158 |
| East Troy | Dousman, North Prairie, Palmyra, Eagle, Sullivan, Helenville | Sullivan 3se | May 3 | Oct 9 | 157 |
| Eden | — | Fond Du Lac Co Ap | May 1 | Oct 10 | 160 |
| Ellison Bay | — | Washington Is | May 15 | Oct 14 | 152 |
| Ephraim | Sister Bay, Baileys Harbor | Ephraim 1ne-wwtp | May 14 | Oct 18 | 155 |
| Fond du Lac | St. Peter, Mount Calvary, St. Cloud, Van Dyne | Fond Du Lac Wwtp | May 1 | Oct 12 | 162 |
| Forestville | — | Forestville-4e | May 6 | Oct 17 | 163 |
| Fort Atkinson | Milton | Ft Atkinson | Apr 28 | Oct 13 | 166 |
| Green Bay | Suamico, Hobart, Howard, Bellevue, Ashwaubenon, De Pere, +3 more | Green Bay | Apr 30 | Oct 9 | 161 |
| Greenville | Harrison, Appleton, Neenah, Kaukauna, Little Chute, Kimberly, +1 more | Appleton | May 4 | Oct 6 | 154 |
| Harrison | Brillion, Forest Junction, Collins, Hilbert, Reedsville, Greenleaf | Brillion | May 6 | Oct 6 | 151 |
| Hingham | Cedar Grove, Oostburg | Hingham Wwtp | May 3 | Oct 16 | 165 |
| Janesville | Footville, Lake Lorraine, Hanover | Afton - Janesville Wwtp | Apr 26 | Oct 15 | 170 |
| Jefferson | — | Jefferson Wwtp | Apr 25 | Oct 18 | 173 |
| Kewaunee | Luxemburg, Algoma, Casco | Kewaunee | May 1 | Oct 18 | 168 |
| Lake Mills | Waterloo, Johnson Creek, Deerfield, Marshall, Rockdale | Lake Mills Wwtp | Apr 29 | Oct 14 | 167 |
| Lowell | Reeseville | Beaver Dam Wwtp | May 2 | Oct 9 | 157 |
| Madison | — | Charmany Farm | Apr 28 | Oct 15 | 169 |
| Madison | Fitchburg | Uw Arboretum - Madison | May 1 | Oct 9 | 161 |
| Manitowoc | Cleveland, Kellnersville | Manitowoc | Apr 30 | Oct 20 | 171 |
| Mequon | Richfield, Germantown, Menomonee Falls, West Bend, Sussex, Cedarburg, +1 more | Germantown | May 6 | Oct 8 | 154 |
| Milwaukee | Franklin, Greenfield, Hales Corners | Milwaukee Mitchell Ap | Apr 19 | Oct 29 | 192 |
| Milwaukee | Mequon, New Berlin, Brookfield, West Allis, Butler | Mt Mary College | Apr 26 | Oct 18 | 173 |
| Mishicot | Maribel, Francis Creek | Two Rivers | Apr 27 | Oct 21 | 175 |
| New Berlin * | Muskego, Vernon, Brookfield, Waukesha, Pewaukee, Mukwonago, +2 more | Waukesha Wwtp | May 1 | Oct 13 | 162 |
| Oconomowoc | Delafield, Okauchee Lake, Merton, Nashotah | Oconomowoc Wwtp | Apr 30 | Oct 12 | 164 |
| Orfordville | Durand | Brodhead Wwtp | Apr 29 | Oct 12 | 165 |
| Oshkosh | Omro, Winneconne, Butte des Morts | Oshkosh | Apr 24 | Oct 20 | 178 |
| Pleasant Prairie | Old Mill Creek | Chicago Waukegan Rgnl Ap | Apr 30 | Oct 21 | 173 |
| Pleasant Prairie | Bristol, Somers | Kenosha Rgnl Ap | Apr 28 | Oct 19 | 174 |
| Pleasant Prairie | — | Kenosha | Apr 19 | Oct 26 | 189 |
| Plymouth | Hingham, Random Lake, Elkhart Lake, Cascade, Greenbush, Batavia | Plymouth Wwtp | May 3 | Oct 10 | 159 |
| Port Washington | Saukville, Waubeka, Belgium | Port Washington | Apr 27 | Oct 22 | 176 |
| Raymond | Mount Pleasant, Yorkville, Eagle Lake | Union Grove | May 5 | Oct 8 | 156 |
| Salem Lakes | Antioch, Lake Villa | Antioch | Apr 23 | Oct 21 | 179 |
| Salem Lakes | Rochester, Bloomfield, Tichigan, Twin Lakes, Burlington, Lake Geneva, +4 more | Burlington | May 5 | Oct 9 | 156 |
| Sharon | Clinton, Darien | Clinton Wwtp | Apr 30 | Oct 10 | 161 |
| Sheboygan Falls | Kohler, Howards Grove, Cleveland | Sheboygan Co Mem Ap | May 5 | Oct 8 | 154 |
| Sobieski | — | Oconto 4 W | May 9 | Oct 6 | 150 |
| Stoughton | McFarland, Cottage Grove, Edgerton, Evansville, Brooklyn | Stoughton | Apr 30 | Oct 11 | 163 |
| Sturgeon Bay | Egg Harbor, Little Sturgeon | Sturgeon Bay Exp Farm | May 8 | Oct 13 | 157 |
| Van Dyne | — | Oshkosh Wittman Ap | Apr 30 | Oct 13 | 165 |
| Watertown | — | Watertown Wwtp | Apr 28 | Oct 12 | 167 |
| West Bend | Kewaskum | W Bend Public Works | May 1 | Oct 12 | 161 |
| Whitewater | Elkhorn | Whitewater | May 2 | Oct 9 | 157 |
| Winchester | — | New London | May 4 | Oct 6 | 153 |
* New Berlin is this group's median-season location — the calendar below is computed from its data.
Data: NOAA NCEI U.S. Climate Normals 1991–2020 (public domain) and USDA Plant Hardiness Zone Map 2023. Planting windows synthesized from U.S. Cooperative Extension guides.
Planting calendar (New Berlin, representative)
Computed from New Berlin's average frost dates — the median-season location in this Wisconsinzone 5b group. hatched = start seeds indoors, solid green = plant out, teal = a fall sowing, and the terracotta dot marks the estimated first harvest. Ranges are extension-guide planning guidance, not guarantees — your own location's dates may run a week or two earlier or later (see the table above).
- Start indoors
- Plant out
- Fall sowing
- First harvest
| Crop | Frost tolerance | Start indoors | Plant out | First harvest | Fall planting | Season fit |
|---|---|---|---|---|---|---|
| Tomato | Tender | Mar 6 – Mar 20 | May 8 – May 15 | Jul 7 – Jul 27 | — | matures comfortably |
| Pepper | Very tender | Feb 20 – Mar 6 | May 15 – May 22 | Jul 14 – Aug 13 | — | matures comfortably |
| Cucumber | Tender | Apr 3 – Apr 10 | May 8 – May 15 | Jun 27 – Jul 17 | — | matures comfortably |
| Summer squash / zucchini | Tender | — | May 8 – May 15 | Jun 22 – Jul 7 | — | matures comfortably |
| Bush bean | Tender | — | May 8 – May 15 | Jun 27 – Jul 7 | Aug 14 – Aug 24 | matures comfortably |
| Sweet corn | Tender | — | May 1 – May 15 | Jun 30 – Jul 30 | — | matures comfortably |
| Basil | Very tender | Mar 20 – Apr 3 | May 8 – May 15 | Jun 7 – Jun 22 | — | matures comfortably |
| Lettuce | Half-hardy | Mar 20 – Apr 3 | Apr 3 – Apr 17 | May 18 – Jun 2 | Jul 31 – Aug 15 | matures comfortably |
| Pea | Hardy | — | Mar 20 – Apr 3 | May 14 – May 29 | Jul 21 – Aug 5 | matures comfortably |
| Spinach | Hardy | — | Mar 20 – Apr 3 | Apr 29 – May 9 | Aug 10 – Aug 20 | matures comfortably |
| Carrot | Half-hardy | — | Apr 10 – Apr 17 | Jun 9 – Jun 29 | Jul 11 – Jul 31 | matures comfortably |
| Broccoli | Half-hardy | Mar 6 – Mar 20 | Apr 3 – Apr 17 | May 28 – Jun 17 | Jul 16 – Aug 5 | matures comfortably |
Which crops fit this growing season
Using New Berlin's own 162-day growing season (32°F, NOAA 1991–2020 median) against each crop's real days-to-maturity range: 12 of 12 crops mature here with comfortable margin. A different location in the table above with a longer or shorter season will get a different mix — the ZIP planner on the home page gives your own.
Frost & freeze dates (New Berlin)
From NOAA's 1991–2020 Climate Normals at station USC00478937. The median (p50) is the average date; the 90%-safe column is the date the freeze has passed in about 9 years out of 10 — the conservative date to plant after or harvest before.
| Threshold | Last spring — avg | Last spring — 90%-safe | First fall — avg | First fall — 90%-safe | Season (days) |
|---|---|---|---|---|---|
| 36°F | May 13 | May 29 | Oct 2 | Oct 15 | 141 |
| 32°F (freeze) | May 1 | May 18 | Oct 13 | Oct 25 | 162 |
| 28°F | Apr 19 | May 5 | Oct 23 | Nov 6 | 185 |
| 24°F | Apr 7 | Apr 21 | Nov 4 | Nov 18 | 210 |
Growing degree days
Growing degree days (GDD) accumulate warmth above a base temperature over the year — a better predictor of crop development than the calendar alone. This group's median GDD (base 50°F) across all 52 locations is 2,530; New Berlin's own reading is shown below.
| Model | °F·days | Used for |
|---|---|---|
| Base 50°F (warm-season) | 2,535 | standard warm-season base (tomato, corn, beans) |
| Base 40°F (cool-season) | 4,513 | cool-season crops (brassicas, greens) |
Hardiness zone 5b in Wisconsin
Zone 5b means an average annual extreme minimum winter temperature of about −15 to −10 °F on the USDA's 2023 map — the number that tells you which perennials, shrubs, and trees reliably survive an average winter here. It does not set your planting dates, which come from the frost calendar above. Wisconsin spans 5 hardiness zones in this dataset — see all Wisconsin locations for the full range, including zones4a, 4b, 5a, 6a.
Explore zone 5b in other states at zone 5b, or see all USDA hardiness zones.
Frequently asked questions
- What does USDA hardiness zone 5b mean in Wisconsin?
- Zone 5b means an average annual extreme minimum winter temperature of −15 to −10 °F — the standard USDA measure of which perennials survive winter. 52 locations in Wisconsin fall in this zone. It does not set planting dates; see the frost calendar below for that.
- Where in Wisconsin's zone 5b is the growing season longest?
- Milwaukee runs the longest season on this page at about 192 days; Bayfield is shortest at about 140 days — they share the same hardiness zone, but they sit at different weather stations, so their frost calendars differ.
- When should I plant tomatoes in Wisconsin's zone 5b?
- Using New Berlin's frost dates (this page's median-season location): start seeds indoors about Mar 6 – Mar 20, then transplant outside about May 8 – May 15. Your own location in the table above may differ by a week or two — use the ZIP planner on the home page for your exact station's dates.
- Does every location in Wisconsin's zone 5b have the same frost dates?
- No — they do not all share a weather station, so frost dates vary by a week or more across the 52 locations listed (see the table above for each location's own dates).
Sources & method
Frost, freeze, growing-season, and growing-degree-day figures are NOAA NCEI U.S. Climate Normals 1991–2020, one reading per location's own nearest station (see the table above). The hardiness zone is the USDA Plant Hardiness Zone Map 2023, matched to each location's ZIP. Planting windows are computed by counting from the average last and first frost using per-crop offsets synthesized from U.S. Cooperative Extension guides — the full method and citations are on the methodology page.