Chicago to Miami — airline reliability comparison
United Airlines is the most reliable airline on the ORD to MIA route with a 80% on-time rate, compared to Frontier Airlines at 65%. Based on 3,575 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 | 80% | 1.0% | 68m | 3,575 |
| American AirlinesAA | 77% | 1.2% | 69m | 10,206 |
| Spirit AirlinesNK | 72% | 2.4% | 69m | 1,731 |
| Frontier AirlinesF9Worst | 65% | 3.1% | 135m | 32 |
Delays, TSA, weather, gates — we'll let you know if something matters.
Data last updated October 2026. Source: Bureau of Transportation Statistics.