San Juan, PR

What the Data Says About SJU

San Juan, PR in San Juan, Puerto Rico handled 366,579 flights in the Bureau of Transportation Statistics dataset between 2020 and 2025, posting a 76.1% on-time departure rate. Of those flights, 87,503 experienced delays, 3,126 were cancelled, and 740 were diverted. The cancellation rate works out to 0.85%, the diversion rate to 0.20%, and the average delay when departures run late is 78.5 minutes. These figures are the baseline for comparing SJU against other airports in the same state and nationally.

Breaking down what drives delays at SJU, Late Aircraft leads the pack. Late Aircraft accounts for 45.2% of total delay minutes, followed by Carrier at 38.4% and NAS (National Aviation System) at 15.3%. Weather contributes 0.9% of delay minutes at this airport, while security holds the smallest share at 0.2%. Travelers often overestimate the weather share; the BTS categorization shows late-arriving aircraft and carrier operations as the larger contributors.

Seasonally, October runs the cleanest at SJU with a 91% on-time rate, while July is the roughest at 85.8% — a 5-point swing between best and worst month. Volume peaks in July, when average flights hit 5,936. The busiest route from SJU is to SJU (San Juan), with 35,205 flights at a 74.1% on-time rate. Combine these numbers — 76.1% on-time, 78.5-minute average delay, 0.85% cancellation rate — and you have a concrete picture of departure reliability at San Juan, PR.