When to plant Winter squash in Illinois

In fall, from June 1 – July 1 in Algonquin to June 20 – July 20 in Wood River.

USDA's earliest safe spring and latest safe fall planting dates, matched to each place's average frost dates.

Winter squash planting dates by place in Illinois
PlaceSpringFall
Addison—June 10 – July 10
Algonquin—June 1 – July 1
Alsip—June 10 – July 10
Alton—June 20 – July 20
Antioch—June 1 – July 1
Arlington Heights—June 10 – July 10
Aurora—June 1 – July 1
Barrington—June 1 – July 1
Bartlett—June 1 – July 1
Batavia—June 1 – July 1
Beach Park—June 1 – July 1
Belleville—June 1 – July 1
Bellwood—June 10 – July 10
Belvidere—June 1 – July 1
Bensenville—June 10 – July 10
Berwyn—June 10 – July 10
Bloomingdale—June 1 – July 1
Bloomington—June 1 – July 1
Blue Island—June 10 – July 10
Bolingbrook—June 1 – July 1
Bourbonnais—June 1 – July 1
Bradley—June 1 – July 1
Bridgeview—June 10 – July 10
Brookfield—June 10 – July 10
Buffalo Grove—June 10 – July 10
Burbank—June 10 – July 10
Burr Ridge—June 1 – July 1
Cahokia Heights—June 10 – July 10
Calumet City—June 1 – July 1
Campton Hills—June 1 – July 1
Canton—June 1 – July 1
Carbondale—June 1 – July 1
Carol Stream—June 1 – July 1
Carpentersville—June 1 – July 1
Cary—June 1 – July 1
Centralia—June 1 – July 1
Champaign—June 1 – July 1
Channahon—June 10 – July 10
Charleston—June 1 – July 1
Chatham—June 1 – July 1
Chicago—June 20 – July 20
Chicago Heights—June 1 – July 1
Chicago Ridge—June 10 – July 10
Cicero—June 10 – July 10
Collinsville—June 10 – July 10
Columbia—June 10 – July 10
Country Club Hills—June 1 – July 1
Crest Hill—June 1 – July 1
Crestwood—June 10 – July 10
Crystal Lake—June 1 – July 1
Danville—June 1 – July 1
Darien—June 1 – July 1
Decatur—June 1 – July 1
Deerfield—June 1 – July 1
DeKalb—June 1 – July 1
Des Plaines—June 10 – July 10
Dixon—June 1 – July 1
Dolton—June 1 – July 1
Downers Grove—June 1 – July 1
East Moline—June 1 – July 1
East Peoria—June 1 – July 1
East St. Louis—June 10 – July 10
Edwardsville—June 20 – July 20
Effingham—June 1 – July 1
Elgin—June 1 – July 1
Elk Grove Village—June 10 – July 10
Elmhurst—June 10 – July 10
Elmwood Park—June 10 – July 10
Evanston—June 1 – July 1
Evergreen Park—June 10 – July 10
Fairview Heights—June 10 – July 10
Forest Park—June 10 – July 10
Fox Lake—June 1 – July 1
Frankfort—June 1 – July 1
Franklin Park—June 10 – July 10
Freeport—June 1 – July 1
Galesburg—June 1 – July 1
Geneva—June 1 – July 1
Glen Carbon—June 20 – July 20
Glen Ellyn—June 1 – July 1
Glendale Heights—June 1 – July 1
Glenview—June 1 – July 1
Godfrey—June 20 – July 20
Granite City—June 20 – July 20
Grayslake—June 1 – July 1
Gurnee—June 1 – July 1
Hanover Park—June 1 – July 1
Harvey—June 1 – July 1
Hazel Crest—June 1 – July 1
Herrin—June 1 – July 1
Hickory Hills—June 1 – July 1
Highland—June 1 – July 1
Highland Park—June 1 – July 1
Hinsdale—June 1 – July 1
Hoffman Estates—June 1 – July 1
Homer Glen—June 1 – July 1
Homewood—June 1 – July 1
Huntley—June 1 – July 1
Jacksonville—June 1 – July 1
Joliet—June 1 – July 1
Justice—June 10 – July 10
Kankakee—June 1 – July 1
Kewanee—June 1 – July 1
La Grange—June 10 – July 10
La Grange Park—June 10 – July 10
Lake Forest—June 1 – July 1
Lake in the Hills—June 1 – July 1
Lake Zurich—June 1 – July 1
Lansing—June 1 – July 1
Lemont—June 1 – July 1
Libertyville—June 1 – July 1
Lincoln—June 1 – July 1
Lincolnwood—June 1 – July 1
Lindenhurst—June 1 – July 1
Lisle—June 1 – July 1
Lockport—June 1 – July 1
Lombard—June 1 – July 1
Loves Park—June 1 – July 1
Lyons—June 10 – July 10
Machesney Park—June 1 – July 1
Macomb—June 1 – July 1
Mahomet—June 1 – July 1
Manhattan—June 1 – July 1
Marion—June 1 – July 1
Markham—June 1 – July 1
Matteson—June 1 – July 1
Mattoon—June 10 – July 10
Maywood—June 10 – July 10
McHenry—June 1 – July 1
Melrose Park—June 10 – July 10
Midlothian—June 10 – July 10
Minooka—June 10 – July 10
Mokena—June 1 – July 1
Moline—June 1 – July 1
Montgomery—June 1 – July 1
Morris—June 1 – July 1
Morton—June 1 – July 1
Morton Grove—June 1 – July 1
Mount Prospect—June 10 – July 10
Mount Vernon—June 1 – July 1
Mundelein—June 1 – July 1
Naperville—June 1 – July 1
New Lenox—June 1 – July 1
Niles—June 10 – July 10
Normal—June 1 – July 1
Norridge—June 10 – July 10
North Aurora—June 1 – July 1
North Chicago—June 1 – July 1
Northbrook—June 1 – July 1
Northlake—June 10 – July 10
O'Fallon—June 1 – July 1
Oak Forest—June 1 – July 1
Oak Lawn—June 10 – July 10
Oak Park—June 10 – July 10
Orland Park—June 1 – July 1
Oswego—June 1 – July 1
Ottawa—June 1 – July 1
Palatine—June 1 – July 1
Palos Heights—June 10 – July 10
Palos Hills—June 1 – July 1
Park Forest—June 1 – July 1
Park Ridge—June 10 – July 10
Pekin—June 1 – July 1
Peoria—June 1 – July 1
Pingree Grove—June 1 – July 1
Plainfield—June 1 – July 1
Plano—June 1 – July 1
Pontiac—June 1 – July 1
Prospect Heights—June 10 – July 10
Quincy—June 10 – July 10
Rantoul—June 1 – July 1
Richton Park—June 1 – July 1
River Forest—June 10 – July 10
River Grove—June 10 – July 10
Riverdale—June 10 – July 10
Rock Island—June 1 – July 1
Rockford—June 1 – July 1
Rolling Meadows—June 10 – July 10
Romeoville—June 1 – July 1
Roscoe—June 1 – July 1
Roselle—June 1 – July 1
Round Lake—June 1 – July 1
Round Lake Beach—June 1 – July 1
Schaumburg—June 1 – July 1
Schiller Park—June 10 – July 10
Shiloh—June 1 – July 1
Shorewood—June 1 – July 1
Skokie—June 1 – July 1
South Elgin—June 1 – July 1
South Holland—June 1 – July 1
Springfield—June 1 – July 1
St. Charles—June 1 – July 1
Sterling—June 1 – July 1
Streamwood—June 1 – July 1
Streator—June 10 – July 10
Summit—June 10 – July 10
Swansea—June 1 – July 1
Sycamore—June 1 – July 1
Taylorville—June 1 – July 1
Tinley Park—June 1 – July 1
Troy—June 1 – July 1
Urbana—June 1 – July 1
Vernon Hills—June 1 – July 1
Villa Park—June 1 – July 1
Warrenville—June 1 – July 1
Washington—June 1 – July 1
Waterloo—June 10 – July 10
Wauconda—June 1 – July 1
Waukegan—June 1 – July 1
West Chicago—June 1 – July 1
Westchester—June 10 – July 10
Western Springs—June 1 – July 1
Westmont—June 1 – July 1
Wheaton—June 1 – July 1
Wheeling—June 10 – July 10
Wilmette—June 1 – July 1
Winfield—June 1 – July 1
Winnetka—June 1 – July 1
Wood Dale—June 10 – July 10
Wood River—June 20 – July 20
Woodridge—June 1 – July 1
Woodstock—June 1 – July 1
Worth—June 10 – July 10
Yorkville—June 1 – July 1
Zion—June 1 – July 1

Planting dates: USDA Home and Garden Bulletin No. 9 (1967), tables 4 and 5. Frost dates: NOAA U.S. Climate Normals 1991–2020. “—” means the place's frost date is outside the table. The full USDA table for winter squash.