Flight International Airport departs from San Francisco International Airport at 23:35 and arrives at Chicago O'Hare International Airport at 16:51.The flight has a short stop at Philadelphia.
The flighttime is about 15h 16m. The distance travelled ("as the bird flies"): 3832 Km. So the average speed is roughly 251 Km.
There is an 2 hour time difference between San Francisco and Chicago