The federal government reports that 90 percent of flights arrived on time at Midway in April. That was the best performance of the nation's 33 busiest airports.
In March, 81 percent of planes arrived on schedule at Midway.
Meanwhile, O'Hare International Airport ranked 12th on the list, with 85 percent of flights arriving on time in April. That's a big improvement for O'Hare which was second to last on the list a year earlier, with only 75 percent of arrivals on time.
A Midway official says the airport was helped in April by good weather and efforts by the airlines to keep on schedule.