O'Hare was 19th with 78-percent.
Houston Inter-Continental was the best and New York's JFK was the worst.
But the departure numbers aren't good for Chicago.
Midway was 30th out of 31 airports with 72.8-percent of flights taking off on time. Only Miami had a lower rate.
O'Hare was 24th.
Portland, Oregon had the best departure rate.