MDW (Chicago) to SJU (San Juan) flights arrive on time 67% of the time. The most reliable airline on this route is Southwest Airlines at 90%. The average delay is 38 minutes. Delays on this route are most often caused by air traffic and busy airspace.
Source: Bureau of Transportation Statistics. Updated May 2026.MDW → SJU
MDW (Chicago) to SJU (San Juan)
MDW → SJU on-time performance by month
24
JanFebMarAprMayJunJulAugSepOctNovDec
Worse
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This route is delayed fairly often. About 67% of flights arrive on schedule.
Delays on this route are most often caused by air traffic and busy airspace.
Accurate?
Southwest Airlines is significantly more reliable on this route at 90% on time vs Frontier Airlines at 69%.
Airline Comparison
Southwest Airlines leads at 90% on time; Frontier Airlines trails at 69%.
Accurate?
Good to know
Departing from MDW
78% on timeTSA is currently ~25 min. Best time: 4 AM (about 5 min).
Arriving at SJU
75% 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 ~19 min right now. Allow at least 60 minutes for a domestic connection.
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Data last updated May 2026. Source: Bureau of Transportation Statistics.