Flight Deals from Chicago O Hare Airport to Philadelphia from $32

Flights from Chicago to Philadelphia peak in late February/March and are cheapest in August/late October, varying by about $150.

When planning your flight from Chicago to Philadelphia, be aware that prices typically peak in late February to early March, with March seeing the highest average prices, around the $280 to $310 range. Conversely, late summer and early autumn, particularly August and late October, offer some of the lowest fares, sometimes dipping below $170. The most abrupt transitions occur in mid-March as prices rise sharply, and again in early November when prices tend to decline sharply. Overall, expect a variation of approximately $150 between high and low seasons.

Book your flight from Chicago to Philadelphia 26-31 days before departure for the best prices; avoid booking within 17 days to prevent high costs.

If you're planning to fly from Chicago to Philadelphia, the best time to purchase your tickets is between 26 to 31 days before your departure date, when prices are at their lowest around $211. Prices beyond this range quickly increase, reaching as high as $375 if you book too early. You’ll want to be cautious of purchasing within 17 days of departure, as prices can soar to $432, making your flight significantly more expensive. For those who prefer early bookings, securing your tickets 72 to 69 days prior can also offer nearly comparable rates but with better seat selection options.