Springfield in November

April through June gives you the best weather without the summer humidity that makes Illinois feel like a swamp. Spring brings the prairie wildflowers, and temperatures hover in the comfortable 60-75°F range. September and October are equally sweet — fall colors peak around mid-October, and you'll get crisp mornings perfect for walking the Lincoln sites. Summer gets sticky, with July temperatures pushing 85°F plus humidity that'll have you sweating through your shirt. But summer also brings the Illinois State Fair in August, which is genuinely worth planning around if you want to see Springfield at its most authentically Midwestern. Winter is cold and gray, though December brings holiday decorations to the historic sites. Spring break timing works well for families, and you'll avoid the summer tourist buses from Chicago.