BOS (Boston) to SJU (San Juan) flights arrive on time 68% of the time. The most reliable airline on this route is Delta Air Lines at 79%. The average delay is 75 minutes. Delays on this route are most often caused by the airline (crew, maintenance, or boarding).
Source: Bureau of Transportation Statistics. Updated August 2026.BOS → SJU
BOS (Boston) to SJU (San Juan)
BOS → SJU on-time performance by month
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JanFebMarAprMayJunJulAugSepOctNovDec
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This route is delayed fairly often. About 68% of flights arrive on schedule.
Delays on this route are most often caused by the airline (crew, maintenance, or boarding).
Accurate?
Delta Air Lines is significantly more reliable on this route at 79% on time vs Frontier Airlines at 48%.
Airline Comparison
Delta Air Lines leads at 79% on time; Frontier Airlines trails at 48%.
Accurate?
Good to know
Departing from BOS
77% on timeExpect ~21 min sitting on the taxiway after your gate pushes back. BOS has long runway queues.
TSA is currently ~5 min. Best time: 4 AM (about 5 min).
Arriving at SJU
76% on timeWhen flights into SJU are late, the average delay is 75 minutes. Build buffer if you have ground plans.
If connecting at SJU: TSA is ~8 min right now. Allow at least 60 minutes for a domestic connection.
Flight cancelled or delayed?
Check what Delta Air Lines owes you — refund rights, action plan, complaint email. Free.
Flying out of BOS? We'll brief you.
Delays, TSA, weather, gates — we'll let you know if something matters.
Know someone flying soon?
Send them the link — delay data, TSA waits, weather, all free.
Data last updated August 2026. Source: Bureau of Transportation Statistics.