BOS (Boston) to SJU (San Juan) flights arrive on time 69% of the time. The most reliable airline on this route is Delta Air Lines at 81%. The average delay is 74 minutes. Delays on this route are most often caused by the airline (crew, maintenance, or boarding).
Source: Bureau of Transportation Statistics. Updated October 2026.BOS → SJU
BOS (Boston) to SJU (San Juan)
BOS → SJU on-time performance by month
24
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JanFebMarAprMayJunJulAugSepOctNovDec
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This route is delayed fairly often. About 69% 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 81% on time vs Frontier Airlines at 48%.
Airline Comparison
Delta Air Lines leads at 81% on time; Frontier Airlines trails at 48%.
Accurate?
Good to know
Departing from BOS
77% on timeExpect ~20 min sitting on the taxiway after your gate pushes back. BOS has long runway queues.
TSA is currently ~33 min. Best time: 4 AM (about 5 min).
Arriving at SJU
75% on timeWhen flights into SJU are late, the average delay is 76 minutes. Build buffer if you have ground plans.
If connecting at SJU: TSA is ~26 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 October 2026. Source: Bureau of Transportation Statistics.