303 - 652 GBP
Travelling from most locations, it is best to book your flight to Chicago during the month of February for the best deal, although there are other times of the year which offer great deals as well.
On average, from most locations, when planning your trip to Chicago, try to book your flight in the region of 51 days in advance for the cheapest prices.
From most locations, the cheapest day to fly to Chicago is Wednesday. Most users found that departing on a Sunday was most expensive.
Typically, cheap prices to Chicago are most often found for evening flights. Cheap prices are less likely for afternoon flights.