How do I know if my flight will be delayed tomorrow?

No tool can predict a specific flight delay with certainty, but you can assess the probability by checking three things the night before:

1. Weather at both airports. Check the NWS forecast for your departure and arrival cities. Winter storms, dense fog, and afternoon thunderstorms are the top three delay causes. If either airport has a severe weather advisory, expect disruption.

2. FAA advisories. The FAA posts ground delay programs (GDPs) and ground stops in advance at fly.faa.gov. If there's already a GDP posted for your destination airport, your flight will likely be delayed. These are usually announced 2-6 hours before they take effect.

3. Your specific aircraft's history that day. Use FlightAware or Flight Check to see if the plane assigned to your flight has been running late all day. Aircraft delays cascade — if your plane was 45 minutes late on its previous leg, it'll likely be late to your gate too.

The single best predictor: time of day. Flights before 8 AM are delayed roughly half as often as flights after 2 PM. If you have flexibility, early morning flights are dramatically more reliable. This isn't speculation — it's consistent across every year of BTS data going back a decade.