Methodology

Data: U.S. Department of Transportation, Bureau of Transportation Statistics, “Reporting Carrier On-Time Performance (1987–present)” monthly files for November and December 2022, 2023, 2024 and 2025 (4,556,515 flight records). U.S. government data, public domain. BTS collects data from U.S. airlines that each account for at least 1% of domestic scheduled passenger revenue (including their regional operators reporting separately). Smaller airlines and some regional operators are not in the data, so airport totals do not include every flight.

Windows: “Thanksgiving week” = the Tuesday before through the Sunday after Thanksgiving (Nov 22–27, 2022; Nov 21–26, 2023; Nov 26–Dec 1, 2024; Nov 25–30, 2025). “Rest of November” = all other November days. “Christmas week” = Dec 20–31. “Early December” = Dec 1–19 excluding any days in the Thanksgiving window. Years are pooled (all flights counted together) unless a table shows years separately.

Measures: Late = arrival 15 or more minutes after schedule (DOT’s definition, field ArrDel15), computed among flights not cancelled or diverted. Cancelled = cancelled flights divided by all scheduled flights in the window. Avg dep. delay = mean departure delay in minutes with early departures counted as zero. Airports are the origin airport (flights leaving it). Airlines are the operating carrier recorded in BTS. Delay-cause shares use BTS cause fields (available for flights that arrived 15+ minutes late) and are the share of reported delay minutes.

Airports: every airport with at least 1,000 scheduled departures in the four Thanksgiving windows combined (80 airports). Airport names come from OurAirports (public domain).

Limits: four years is a small sample for any single airport-day, and one storm can dominate a year (we show year-by-year numbers for that reason). Results describe the past and are not a forecast for your flight. Data for November–December 2026 will be added after BTS publishes it (usually about two months later).