Chicago to San Juan — airline reliability comparison
United Airlines is the most reliable airline on the ORD to SJU route with a 82% on-time rate, compared to Frontier Airlines at 68%. Based on 1,968 flights tracked.
This route involves weather-prone airports and high-congestion airports, which can affect reliability regardless of airline.
Source: Bureau of Transportation Statistics. Updated October 2026.| Airline | On-Time % | Cancel % | Avg Delay | Flights |
|---|---|---|---|---|
| United AirlinesUABest | 82% | 0.2% | 55m | 1,968 |
| American AirlinesAA | 79% | 0.5% | 56m | 1,150 |
| Spirit AirlinesNK | 77% | 1.8% | 68m | 1,192 |
| Frontier AirlinesF9Worst | 68% | 5.2% | 147m | 40 |
Delays, TSA, weather, gates — we'll let you know if something matters.
Data last updated October 2026. Source: Bureau of Transportation Statistics.