An estimated 47.5 million passengers will fly in the U.S. between Dec. 19 and Jan. 5, 2020, according to a holiday travel forecast from the trade group Airlines for America. While the vast majority will reach their destinations on time, flights from certain airports, including major hubs, and those operated by certain airlines are more likely to face late arrivals in December, NBC News reports.
If your plane doesn’t land on time, it’s highly likely that the weather was to blame. “Weather is the most common cause of delays year round,” a spokesperson for the Federal Aviation Administration wrote to NBC News via email, accounting for close to 7 out of 10 delays between 2008 and 2013.
It isn’t just winter storms like the kind that snarled flights across the country for Thanksgiving: In winter, pilots are more prone to run into strong winds and low-visibility issues. Other than weather, air travel can be delayed by equipment failure, runway congestion and passenger volume.