What causes a ground stop at an airport?

A ground stop means the FAA has ordered all flights bound for a specific airport to stay on the ground at their departure airports. No new departures toward the affected airport are allowed until the ground stop lifts. Flights already in the air continue to their destination.

The most common causes:

Weather (60-70% of ground stops): Thunderstorms, low visibility fog, heavy snow, or wind shear at the destination airport. JFK, EWR, and SFO are the most frequent ground stop recipients due to weather.

Volume/capacity (20-25%): When traffic demand exceeds the airport's capacity — often because bad weather reduced the number of available runways. An airport that normally handles 80 arrivals/hour might drop to 40, triggering a ground stop until the backlog clears.

Equipment/infrastructure (5-10%): Runway closures for maintenance, power outages, or navigation system failures. These are rarer but can last longer.

Security events (rare): TSA checkpoint evacuations, security breaches, or VIP movements (presidential TFRs).

A ground stop is different from a ground delay program (GDP). A GDP slows traffic by assigning specific departure times to reduce congestion; a ground stop halts it entirely. Ground stops average 30-90 minutes but can extend for hours during severe weather. Check fly.faa.gov for real-time status.