USDA hardiness zones in Illinois
| Zone | Avg. extreme minimum | ZIP codes | Example cities |
|---|---|---|---|
| Zone 5a | −20 to −15°F | 33 | Freeport |
| Zone 5b | −15 to −10°F | 403 | Aurora, Naperville, Joliet, Rockford |
| Zone 6a | −10 to −5°F | 555 | Chicago, Springfield, Peoria, Champaign |
| Zone 6b | −5 to 0°F | 226 | Godfrey, Mount Vernon, Effingham, Centralia |
| Zone 7a | 0 to 5°F | 160 | Belleville, O'Fallon, Granite City, Edwardsville |
Growing zone and frost dates by city
| City | Zone | Frost dates |
|---|---|---|
| Chicago | 6a (−10 to −5°F) | Chicago frost dates |
| Aurora | 5b (−15 to −10°F) | Aurora frost dates |
| Naperville | 5b (−15 to −10°F) | Naperville frost dates |
| Joliet | 5b (−15 to −10°F) | Joliet frost dates |
| Rockford | 5b (−15 to −10°F) | Rockford frost dates |
| Elgin | 5b (−15 to −10°F) | Elgin frost dates |
| Springfield | 6a (−10 to −5°F) | Springfield frost dates |
| Peoria | 6a (−10 to −5°F) | Peoria frost dates |
| Champaign | 6a (−10 to −5°F) | Champaign frost dates |
| Waukegan | 6a (−10 to −5°F) | Waukegan frost dates |
| Cicero | 6a (−10 to −5°F) | Cicero frost dates |
| Bloomington | 6a (−10 to −5°F) | Bloomington frost dates |
| Schaumburg | 5b (−15 to −10°F) | Schaumburg frost dates |
| Evanston | 6a (−10 to −5°F) | Evanston frost dates |
| Arlington Heights | 6a (−10 to −5°F) | Arlington Heights frost dates |
| Bolingbrook | 6a (−10 to −5°F) | Bolingbrook frost dates |
| Decatur | 6a (−10 to −5°F) | Decatur frost dates |
| Skokie | 6a (−10 to −5°F) | Skokie frost dates |
| Palatine | 5b (−15 to −10°F) | Palatine frost dates |
| Des Plaines | 6a (−10 to −5°F) | Des Plaines frost dates |
| Orland Park | 6a (−10 to −5°F) | Orland Park frost dates |
| Oak Lawn | 6a (−10 to −5°F) | Oak Lawn frost dates |
| Mount Prospect | 6a (−10 to −5°F) | Mount Prospect frost dates |
| Tinley Park | 6a (−10 to −5°F) | Tinley Park frost dates |
| Berwyn | 6a (−10 to −5°F) | Berwyn frost dates |
| Wheaton | 5b (−15 to −10°F) | Wheaton frost dates |
| Normal | 6a (−10 to −5°F) | Normal frost dates |
| Oak Park | 6a (−10 to −5°F) | Oak Park frost dates |
| Hoffman Estates | 5b (−15 to −10°F) | Hoffman Estates frost dates |
| Downers Grove | 6a (−10 to −5°F) | Downers Grove frost dates |
| Plainfield | 5b (−15 to −10°F) | Plainfield frost dates |
| Glenview | 6a (−10 to −5°F) | Glenview frost dates |
| Elmhurst | 6a (−10 to −5°F) | Elmhurst frost dates |
| Lombard | 6a (−10 to −5°F) | Lombard frost dates |
| Buffalo Grove | 6a (−10 to −5°F) | Buffalo Grove frost dates |
| Moline | 5b (−15 to −10°F) | Moline frost dates |
| Crystal Lake | 5b (−15 to −10°F) | Crystal Lake frost dates |
| Romeoville | 6a (−10 to −5°F) | Romeoville frost dates |
| Bartlett | 5b (−15 to −10°F) | Bartlett frost dates |
| DeKalb | 5b (−15 to −10°F) | DeKalb frost dates |
| Belleville | 7a (0 to 5°F) | Belleville frost dates |
| Oswego | 5b (−15 to −10°F) | Oswego frost dates |
| Urbana | 6a (−10 to −5°F) | Urbana frost dates |
| Carol Stream | 5b (−15 to −10°F) | Carol Stream frost dates |
| Quincy | 6a (−10 to −5°F) | Quincy frost dates |
| Park Ridge | 6a (−10 to −5°F) | Park Ridge frost dates |
| Wheeling | 6a (−10 to −5°F) | Wheeling frost dates |
| Streamwood | 5b (−15 to −10°F) | Streamwood frost dates |
| Carpentersville | 5b (−15 to −10°F) | Carpentersville frost dates |
| Hanover Park | 5b (−15 to −10°F) | Hanover Park frost dates |
| Rock Island | 5b (−15 to −10°F) | Rock Island frost dates |
| Addison | 6a (−10 to −5°F) | Addison frost dates |
| Calumet City | 6a (−10 to −5°F) | Calumet City frost dates |
| Northbrook | 6a (−10 to −5°F) | Northbrook frost dates |
| North Chicago | 6a (−10 to −5°F) | North Chicago frost dates |
| Woodridge | 6a (−10 to −5°F) | Woodridge frost dates |
| St. Charles | 5b (−15 to −10°F) | St. Charles frost dates |
| Mundelein | 5b (−15 to −10°F) | Mundelein frost dates |
| O'Fallon | 7a (0 to 5°F) | O'Fallon frost dates |
| Glendale Heights | 5b (−15 to −10°F) | Glendale Heights frost dates |
| Elk Grove Village | 6a (−10 to −5°F) | Elk Grove Village frost dates |
| Pekin | 6a (−10 to −5°F) | Pekin frost dates |
| Algonquin | 5b (−15 to −10°F) | Algonquin frost dates |
| Highland Park | 6a (−10 to −5°F) | Highland Park frost dates |
| Gurnee | 6a (−10 to −5°F) | Gurnee frost dates |
| Niles | 6a (−10 to −5°F) | Niles frost dates |
| McHenry | 5b (−15 to −10°F) | McHenry frost dates |
| Huntley | 5b (−15 to −10°F) | Huntley frost dates |
| New Lenox | 6a (−10 to −5°F) | New Lenox frost dates |
| Glen Ellyn | 5b (−15 to −10°F) | Glen Ellyn frost dates |
| Lake in the Hills | 5b (−15 to −10°F) | Lake in the Hills frost dates |
| Galesburg | 5b (−15 to −10°F) | Galesburg frost dates |
| Burbank | 6a (−10 to −5°F) | Burbank frost dates |
| Danville | 6a (−10 to −5°F) | Danville frost dates |
| Lansing | 6a (−10 to −5°F) | Lansing frost dates |
| Lockport | 6a (−10 to −5°F) | Lockport frost dates |
| Wilmette | 6a (−10 to −5°F) | Wilmette frost dates |
| Round Lake Beach | 5b (−15 to −10°F) | Round Lake Beach frost dates |
| Vernon Hills | 6a (−10 to −5°F) | Vernon Hills frost dates |
| Granite City | 7a (0 to 5°F) | Granite City frost dates |
| Oak Forest | 6a (−10 to −5°F) | Oak Forest frost dates |
| Yorkville | 5b (−15 to −10°F) | Yorkville frost dates |
| Batavia | 5b (−15 to −10°F) | Batavia frost dates |
| Chicago Heights | 6a (−10 to −5°F) | Chicago Heights frost dates |
| Edwardsville | 7a (0 to 5°F) | Edwardsville frost dates |
| Woodstock | 5b (−15 to −10°F) | Woodstock frost dates |
| South Elgin | 5b (−15 to −10°F) | South Elgin frost dates |
| Belvidere | 5b (−15 to −10°F) | Belvidere frost dates |
| West Chicago | 5b (−15 to −10°F) | West Chicago frost dates |
| Alton | 7a (0 to 5°F) | Alton frost dates |
| Homer Glen | 6a (−10 to −5°F) | Homer Glen frost dates |
| Morton Grove | 6a (−10 to −5°F) | Morton Grove frost dates |
| Zion | 6a (−10 to −5°F) | Zion frost dates |
| Westmont | 6a (−10 to −5°F) | Westmont frost dates |
| Melrose Park | 6a (−10 to −5°F) | Melrose Park frost dates |
| Collinsville | 7a (0 to 5°F) | Collinsville frost dates |
| Loves Park | 5b (−15 to −10°F) | Loves Park frost dates |
| Rolling Meadows | 6a (−10 to −5°F) | Rolling Meadows frost dates |
| Elmwood Park | 6a (−10 to −5°F) | Elmwood Park frost dates |
| Lisle | 5b (−15 to −10°F) | Lisle frost dates |
| Kankakee | 5b (−15 to −10°F) | Kankakee frost dates |
| Maywood | 6a (−10 to −5°F) | Maywood frost dates |
| Freeport | 5a (−20 to −15°F) | Freeport frost dates |
| Machesney Park | 5b (−15 to −10°F) | Machesney Park frost dates |
| Roselle | 5b (−15 to −10°F) | Roselle frost dates |
| Bloomingdale | 5b (−15 to −10°F) | Bloomingdale frost dates |
| East Peoria | 6a (−10 to −5°F) | East Peoria frost dates |
| Darien | 6a (−10 to −5°F) | Darien frost dates |
| Montgomery | 5b (−15 to −10°F) | Montgomery frost dates |
| Villa Park | 6a (−10 to −5°F) | Villa Park frost dates |
| Carbondale | 7a (0 to 5°F) | Carbondale frost dates |
| Blue Island | 6a (−10 to −5°F) | Blue Island frost dates |
| Frankfort | 6a (−10 to −5°F) | Frankfort frost dates |
| Grayslake | 5b (−15 to −10°F) | Grayslake frost dates |
| Geneva | 5b (−15 to −10°F) | Geneva frost dates |
| Park Forest | 6a (−10 to −5°F) | Park Forest frost dates |
| South Holland | 6a (−10 to −5°F) | South Holland frost dates |
| Libertyville | 6a (−10 to −5°F) | Libertyville frost dates |
| Crest Hill | 6a (−10 to −5°F) | Crest Hill frost dates |
| Dolton | 6a (−10 to −5°F) | Dolton frost dates |
| East Moline | 5b (−15 to −10°F) | East Moline frost dates |
| Mokena | 6a (−10 to −5°F) | Mokena frost dates |
| Lake Zurich | 5b (−15 to −10°F) | Lake Zurich frost dates |
| Harvey | 6a (−10 to −5°F) | Harvey frost dates |
| Lake Forest | 6a (−10 to −5°F) | Lake Forest frost dates |
| Deerfield | 6a (−10 to −5°F) | Deerfield frost dates |
| North Aurora | 5b (−15 to −10°F) | North Aurora frost dates |
| Evergreen Park | 6a (−10 to −5°F) | Evergreen Park frost dates |
| Sycamore | 5b (−15 to −10°F) | Sycamore frost dates |
| Brookfield | 6a (−10 to −5°F) | Brookfield frost dates |
| Homewood | 6a (−10 to −5°F) | Homewood frost dates |
| Ottawa | 5b (−15 to −10°F) | Ottawa frost dates |
| Matteson | 6a (−10 to −5°F) | Matteson frost dates |
| Shorewood | 5b (−15 to −10°F) | Shorewood frost dates |
| Round Lake | 5b (−15 to −10°F) | Round Lake frost dates |
| Bensenville | 6a (−10 to −5°F) | Bensenville frost dates |
| Lemont | 6a (−10 to −5°F) | Lemont frost dates |
| Alsip | 6a (−10 to −5°F) | Alsip frost dates |
| Bellwood | 6a (−10 to −5°F) | Bellwood frost dates |
| Franklin Park | 6a (−10 to −5°F) | Franklin Park frost dates |
| Palos Hills | 6a (−10 to −5°F) | Palos Hills frost dates |
| Cary | 5b (−15 to −10°F) | Cary frost dates |
| Jacksonville | 6a (−10 to −5°F) | Jacksonville frost dates |
| East St. Louis | 7a (0 to 5°F) | East St. Louis frost dates |
| Bourbonnais | 5b (−15 to −10°F) | Bourbonnais frost dates |
| Godfrey | 6b (−5 to 0°F) | Godfrey frost dates |
| Hinsdale | 6a (−10 to −5°F) | Hinsdale frost dates |
| Morton | 6a (−10 to −5°F) | Morton frost dates |
| Charleston | 6a (−10 to −5°F) | Charleston frost dates |
| Marion | 7a (0 to 5°F) | Marion frost dates |
| Cahokia Heights | 7a (0 to 5°F) | Cahokia Heights frost dates |
| Mattoon | 6a (−10 to −5°F) | Mattoon frost dates |
| Bridgeview | 6a (−10 to −5°F) | Bridgeview frost dates |
| Westchester | 6a (−10 to −5°F) | Westchester frost dates |
| Country Club Hills | 6a (−10 to −5°F) | Country Club Hills frost dates |
| Fairview Heights | 7a (0 to 5°F) | Fairview Heights frost dates |
| La Grange | 6a (−10 to −5°F) | La Grange frost dates |
| Washington | 6a (−10 to −5°F) | Washington frost dates |
| Prospect Heights | 6a (−10 to −5°F) | Prospect Heights frost dates |
| Bradley | 5b (−15 to −10°F) | Bradley frost dates |
| Warrenville | 5b (−15 to −10°F) | Warrenville frost dates |
| Antioch | 5b (−15 to −10°F) | Antioch frost dates |
| Lindenhurst | 5b (−15 to −10°F) | Lindenhurst frost dates |
| Norridge | 6a (−10 to −5°F) | Norridge frost dates |
| Morris | 5b (−15 to −10°F) | Morris frost dates |
| Shiloh | 7a (0 to 5°F) | Shiloh frost dates |
| Dixon | 5b (−15 to −10°F) | Dixon frost dates |
| Chatham | 6a (−10 to −5°F) | Chatham frost dates |
| Channahon | 5b (−15 to −10°F) | Channahon frost dates |
| Macomb | 6a (−10 to −5°F) | Macomb frost dates |
| Sterling | 5b (−15 to −10°F) | Sterling frost dates |
| Swansea | 7a (0 to 5°F) | Swansea frost dates |
| Mount Vernon | 6b (−5 to 0°F) | Mount Vernon frost dates |
| Beach Park | 6a (−10 to −5°F) | Beach Park frost dates |
| Hickory Hills | 6a (−10 to −5°F) | Hickory Hills frost dates |
| Wood Dale | 6a (−10 to −5°F) | Wood Dale frost dates |
| Chicago Ridge | 6a (−10 to −5°F) | Chicago Ridge frost dates |
| Wauconda | 5b (−15 to −10°F) | Wauconda frost dates |
| Glen Carbon | 7a (0 to 5°F) | Glen Carbon frost dates |
| Midlothian | 6a (−10 to −5°F) | Midlothian frost dates |
| Forest Park | 6a (−10 to −5°F) | Forest Park frost dates |
| Western Springs | 6a (−10 to −5°F) | Western Springs frost dates |
| La Grange Park | 6a (−10 to −5°F) | La Grange Park frost dates |
| Canton | 6a (−10 to −5°F) | Canton frost dates |
| Lincolnwood | 6a (−10 to −5°F) | Lincolnwood frost dates |
| Hazel Crest | 6a (−10 to −5°F) | Hazel Crest frost dates |
| Lincoln | 6a (−10 to −5°F) | Lincoln frost dates |
| Minooka | 5b (−15 to −10°F) | Minooka frost dates |
| Plano | 5b (−15 to −10°F) | Plano frost dates |
| Pingree Grove | 5b (−15 to −10°F) | Pingree Grove frost dates |
| Winnetka | 6a (−10 to −5°F) | Winnetka frost dates |
| Richton Park | 6a (−10 to −5°F) | Richton Park frost dates |
| Northlake | 6a (−10 to −5°F) | Northlake frost dates |
| Effingham | 6b (−5 to 0°F) | Effingham frost dates |
| Justice | 6a (−10 to −5°F) | Justice frost dates |
| Herrin | 7a (0 to 5°F) | Herrin frost dates |
| Streator | 5b (−15 to −10°F) | Streator frost dates |
| Kewanee | 5b (−15 to −10°F) | Kewanee frost dates |
| Palos Heights | 6a (−10 to −5°F) | Palos Heights frost dates |
| Rantoul | 6a (−10 to −5°F) | Rantoul frost dates |
| Troy | 7a (0 to 5°F) | Troy frost dates |
| Centralia | 6b (−5 to 0°F) | Centralia frost dates |
| River Forest | 6a (−10 to −5°F) | River Forest frost dates |
| Schiller Park | 6a (−10 to −5°F) | Schiller Park frost dates |
| Markham | 6a (−10 to −5°F) | Markham frost dates |
| Burr Ridge | 6a (−10 to −5°F) | Burr Ridge frost dates |
| Waterloo | 7a (0 to 5°F) | Waterloo frost dates |
| Roscoe | 5b (−15 to −10°F) | Roscoe frost dates |
| Manhattan | 6a (−10 to −5°F) | Manhattan frost dates |
| Campton Hills | 5b (−15 to −10°F) | Campton Hills frost dates |
| Columbia | 7a (0 to 5°F) | Columbia frost dates |
| Fox Lake | 5b (−15 to −10°F) | Fox Lake frost dates |
| Pontiac | 6a (−10 to −5°F) | Pontiac frost dates |
| Summit | 6a (−10 to −5°F) | Summit frost dates |
| Worth | 6a (−10 to −5°F) | Worth frost dates |
| Barrington | 5b (−15 to −10°F) | Barrington frost dates |
| Crestwood | 6a (−10 to −5°F) | Crestwood frost dates |
| Taylorville | 6a (−10 to −5°F) | Taylorville frost dates |
| Mahomet | 6a (−10 to −5°F) | Mahomet frost dates |
| Lyons | 6a (−10 to −5°F) | Lyons frost dates |
| River Grove | 6a (−10 to −5°F) | River Grove frost dates |
| Riverdale | 6a (−10 to −5°F) | Riverdale frost dates |
| Wood River | 7a (0 to 5°F) | Wood River frost dates |
| Winfield | 5b (−15 to −10°F) | Winfield frost dates |
| Highland | 6b (−5 to 0°F) | Highland frost dates |
| Peru | 5b (−15 to −10°F) | Peru frost dates |
| Hawthorn Woods | 5b (−15 to −10°F) | Hawthorn Woods frost dates |
| Sauk Village | 6a (−10 to −5°F) | Sauk Village frost dates |
| Harvard | 5b (−15 to −10°F) | Harvard frost dates |
| Rochelle | 5b (−15 to −10°F) | Rochelle frost dates |
| Itasca | 6a (−10 to −5°F) | Itasca frost dates |
| LaSalle | 5b (−15 to −10°F) | LaSalle frost dates |
| Sugar Grove | 5b (−15 to −10°F) | Sugar Grove frost dates |
| Flossmoor | 6a (−10 to −5°F) | Flossmoor frost dates |
| Steger | 6a (−10 to −5°F) | Steger frost dates |
| Lynwood | 6a (−10 to −5°F) | Lynwood frost dates |
| Hampshire | 5b (−15 to −10°F) | Hampshire frost dates |
| Mascoutah | 6b (−5 to 0°F) | Mascoutah frost dates |
| Bethalto | 6b (−5 to 0°F) | Bethalto frost dates |
| Manteno | 5b (−15 to −10°F) | Manteno frost dates |
| Willowbrook | 6a (−10 to −5°F) | Willowbrook frost dates |
| Savoy | 6a (−10 to −5°F) | Savoy frost dates |
| Gilberts | 5b (−15 to −10°F) | Gilberts frost dates |
| Riverside | 6a (−10 to −5°F) | Riverside frost dates |
| Harwood Heights | 6a (−10 to −5°F) | Harwood Heights frost dates |
| Glencoe | 6a (−10 to −5°F) | Glencoe frost dates |
| Lake Villa | 5b (−15 to −10°F) | Lake Villa frost dates |
| Clarendon Hills | 6a (−10 to −5°F) | Clarendon Hills frost dates |
| Monmouth | 5b (−15 to −10°F) | Monmouth frost dates |
| West Dundee | 5b (−15 to −10°F) | West Dundee frost dates |
| Rock Falls | 5b (−15 to −10°F) | Rock Falls frost dates |
| Glenwood | 6a (−10 to −5°F) | Glenwood frost dates |
| Maryville | 7a (0 to 5°F) | Maryville frost dates |
| Jerseyville | 6b (−5 to 0°F) | Jerseyville frost dates |
| Olney | 6b (−5 to 0°F) | Olney frost dates |
| Crete | 6a (−10 to −5°F) | Crete frost dates |
| Long Grove | 5b (−15 to −10°F) | Long Grove frost dates |
| Hillside | 6a (−10 to −5°F) | Hillside frost dates |
| Oak Brook | 6a (−10 to −5°F) | Oak Brook frost dates |
| Island Lake | 5b (−15 to −10°F) | Island Lake frost dates |
| Paris | 6a (−10 to −5°F) | Paris frost dates |
| South Beloit | 5b (−15 to −10°F) | South Beloit frost dates |
| Silvis | 5b (−15 to −10°F) | Silvis frost dates |
| Lincolnshire | 6a (−10 to −5°F) | Lincolnshire frost dates |
| Harrisburg | 7a (0 to 5°F) | Harrisburg frost dates |
| Park City | 6a (−10 to −5°F) | Park City frost dates |
| Broadview | 6a (−10 to −5°F) | Broadview frost dates |
| Rockton | 5b (−15 to −10°F) | Rockton frost dates |
| Round Lake Park | 5b (−15 to −10°F) | Round Lake Park frost dates |
| Marengo | 5b (−15 to −10°F) | Marengo frost dates |
| Princeton | 5b (−15 to −10°F) | Princeton frost dates |
| Greenville | 6b (−5 to 0°F) | Greenville frost dates |
| Inverness | 5b (−15 to −10°F) | Inverness frost dates |
| Sandwich | 5b (−15 to −10°F) | Sandwich frost dates |
| Robinson | 6b (−5 to 0°F) | Robinson frost dates |
| North Riverside | 6a (−10 to −5°F) | North Riverside frost dates |
| Vandalia | 6b (−5 to 0°F) | Vandalia frost dates |
| West Frankfort | 7a (0 to 5°F) | West Frankfort frost dates |
| Elburn | 5b (−15 to −10°F) | Elburn frost dates |
| Salem | 6b (−5 to 0°F) | Salem frost dates |
| University Park | 6a (−10 to −5°F) | University Park frost dates |
| Murphysboro | 7a (0 to 5°F) | Murphysboro frost dates |
| Stickney | 6a (−10 to −5°F) | Stickney frost dates |
| Mendota | 5b (−15 to −10°F) | Mendota frost dates |
| Chester | 7a (0 to 5°F) | Chester frost dates |
| Volo | 5b (−15 to −10°F) | Volo frost dates |
| Clinton | 6a (−10 to −5°F) | Clinton frost dates |
| Calumet Park | 6a (−10 to −5°F) | Calumet Park frost dates |
| Mount Carmel | 6b (−5 to 0°F) | Mount Carmel frost dates |
| Orland Hills | 6a (−10 to −5°F) | Orland Hills frost dates |
| Litchfield | 6b (−5 to 0°F) | Litchfield frost dates |
| Benton | 7a (0 to 5°F) | Benton frost dates |
| Winthrop Harbor | 6a (−10 to −5°F) | Winthrop Harbor frost dates |
| Geneseo | 5b (−15 to −10°F) | Geneseo frost dates |
| Lakemoor | 5b (−15 to −10°F) | Lakemoor frost dates |
| Johnsburg | 5b (−15 to −10°F) | Johnsburg frost dates |
| Countryside | 6a (−10 to −5°F) | Countryside frost dates |
| Braidwood | 5b (−15 to −10°F) | Braidwood frost dates |
| Hillsboro | 6b (−5 to 0°F) | Hillsboro frost dates |
| Monticello | 6a (−10 to −5°F) | Monticello frost dates |
| Chillicothe | 6a (−10 to −5°F) | Chillicothe frost dates |
| Pontoon Beach | 7a (0 to 5°F) | Pontoon Beach frost dates |
| Mount Zion | 6a (−10 to −5°F) | Mount Zion frost dates |
| Carterville | 7a (0 to 5°F) | Carterville frost dates |
| Coal City | 5b (−15 to −10°F) | Coal City frost dates |
| Bartonville | 6a (−10 to −5°F) | Bartonville frost dates |
| Willow Springs | 6a (−10 to −5°F) | Willow Springs frost dates |
| Peoria Heights | 6a (−10 to −5°F) | Peoria Heights frost dates |
| Metropolis | 7a (0 to 5°F) | Metropolis frost dates |
| Beardstown | 6a (−10 to −5°F) | Beardstown frost dates |
| Northfield | 6a (−10 to −5°F) | Northfield frost dates |
| East Alton | 7a (0 to 5°F) | East Alton frost dates |
| Wilmington | 5b (−15 to −10°F) | Wilmington frost dates |
| Wonder Lake | 5b (−15 to −10°F) | Wonder Lake frost dates |
| Du Quoin | 7a (0 to 5°F) | Du Quoin frost dates |
| Lake Bluff | 6a (−10 to −5°F) | Lake Bluff frost dates |
| Genoa | 5b (−15 to −10°F) | Genoa frost dates |
| Spring Grove | 5b (−15 to −10°F) | Spring Grove frost dates |
| Carlinville | 6b (−5 to 0°F) | Carlinville frost dates |
| Spring Valley | 5b (−15 to −10°F) | Spring Valley frost dates |
| Posen | 6a (−10 to −5°F) | Posen frost dates |
| Highwood | 6a (−10 to −5°F) | Highwood frost dates |
| Poplar Grove | 5b (−15 to −10°F) | Poplar Grove frost dates |
| Berkeley | 6a (−10 to −5°F) | Berkeley frost dates |
| Lake Barrington | 5b (−15 to −10°F) | Lake Barrington frost dates |
| Eureka | 5b (−15 to −10°F) | Eureka frost dates |
| Monee | 6a (−10 to −5°F) | Monee frost dates |
| South Barrington | 5b (−15 to −10°F) | South Barrington frost dates |
| Milan | 5b (−15 to −10°F) | Milan frost dates |
| Pana | 6b (−5 to 0°F) | Pana frost dates |
Frequently asked questions
What growing zone is Illinois in?
Illinois’s ZIP codes span USDA zones 5a to 7a, and 6a is the most common. Zones vary with elevation and distance from water, so check your own ZIP code.
When should I plant?
Hardiness zones are about winter cold, not planting dates. For timing, use the last spring frost date for your city on our Illinois frost dates page.