Flight Deals from Seattle to Chicago from $127

Flying from Seattle to Chicago is most expensive in late December and summer, with low fares in early February and mid-October.

When flying from Seattle to Chicago, the most expensive times are typically during late December, with prices peaking significantly at the end of the month, and throughout the summer months, particularly from late June to early August. Conversely, you will find the most affordable flights in early February and again in mid-October, where prices can drop notably. There’s a clear shift in price around mid-December as holiday travel spikes, while prices abruptly decline after early January. Expect high prices in late spring to early summer, with variations ranging from mid $300s to high $400s, while low prices sit below the $250 mark.

Book your flight from Seattle to Chicago about 170 days before departure for the best prices; avoid waiting as costs rise significantly closer to departure.

When planning your trip from Seattle to Chicago, the ideal time to book is approximately 170 days before departure, as prices are lowest, around $200. If you wait too long, prices steadily increase, reaching $589 if booked earlier than this. After 170 days, it's advisable to book before the 47-day mark to avoid rising costs. Between 47 and 17 days before departure, prices will rise significantly, starting around $265 and can soar to $411 as the departure date approaches, with last-minute bookings potentially costing 35% more. Thus, for peace of mind and savings, aim to purchase your tickets early.