MDW (Chicago) to SJU (San Juan) flights arrive on time 69% of the time. The most reliable airline on this route is Southwest Airlines at 90%. The average delay is 61 minutes. Delays on this route are most often caused by the airline (crew, maintenance, or boarding).
Source: Bureau of Transportation Statistics. Updated October 2026.MDW → SJU
MDW (Chicago) to SJU (San Juan)
MDW → SJU on-time performance by month
23
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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?
Southwest Airlines is significantly more reliable on this route at 90% on time vs Frontier Airlines at 72%.
Airline Comparison
Southwest Airlines leads at 90% on time; Frontier Airlines trails at 72%.
Accurate?
Good to know
Departing from MDW
79% on timeTSA is currently ~16 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 ~15 min right now. Allow at least 60 minutes for a domestic connection.
Flight cancelled or delayed?
Check what Southwest Airlines owes you — refund rights, action plan, complaint email. Free.
Flying out of MDW? 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.