United Airlines is the most reliable airline on the IAD to MIA route with a 86% on-time rate, compared to Frontier Airlines at 65%. Based on 1,761 flights tracked.
Source: Bureau of Transportation Statistics. Updated October 2026.Best Airline: IAD to MIA
Washington to Miami — airline reliability comparison
On-Time Rate by Airline
United Airlines86%
Frontier Airlines65%
IAD to MIA Airline Comparison
| Airline | On-Time % | Cancel % | Avg Delay | Flights |
|---|---|---|---|---|
| United AirlinesUABest | 86% | 0.9% | 61m | 1,761 |
| Frontier AirlinesF9Worst | 65% | 1.9% | 79m | 151 |
Route Overview
83%
Overall On-Time
65m
Avg Delay
1.1%
Cancel Rate
1,927
Total Flights
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Data last updated October 2026. Source: Bureau of Transportation Statistics.