Book morning flights
This is the single most effective thing you can do. Flights before 9 AM have a 85-90% on-time rate. After 5 PM, it drops to 70-75%.
Choose your airport wisely
If you have options, avoid delay-prone airports. Flying from Oakland instead of SFO, Burbank instead of LAX, or Midway instead of O'Hare can make a big difference.
Fly Tuesday or Wednesday
The best days have 4-5% higher on-time rates than the worst (Friday).
Avoid connecting flights
Every connection doubles your delay risk. A direct flight has one chance to be delayed; a connection has two. If you must connect, leave 2+ hours between flights.
Travel in September-October
The sweet spot: summer storms are over, winter hasn't started, and passenger volumes are lower.