Miami to San Juan

What the Data Says About MIA to SJU

The Miami to San Juan corridor (MIA → SJU) covers roughly 1,045 miles and is served by 8 carriers, based on Bureau of Transportation Statistics reporting. Across 14,957 flights in the dataset, this route posts a 78.3% on-time rate with an average delay of 73.1 minutes when flights run late. Over the most recent 24 months of BTS data, 5,553 flights were recorded on this pairing — 42 cancelled (0.8%) and 8 diverted (0.1%). Those baseline metrics tell you what to expect before you book.

Having 8 carriers on the route matters: more carriers generally means more daily schedule options, competitive pricing, and redundancy when flights are cancelled. With 14,957 total flights analyzed, the 78.3% on-time figure is statistically meaningful rather than a small-sample fluke. The 73.1-minute average delay applies only to flights that actually ran late, so it is not the average wait across all departures — the majority of flights on this route depart on time under the BTS definition of a delay (15+ minutes past schedule).

Looking at recent months, Oct 2024 posted the best performance on this corridor at 90% on-time, while Jul 2025 came in at 63% on-time — a 28-point gap between best and worst recent month. For travelers evaluating the MIA to SJU route, the combination of a 78.3% on-time rate, 73.1-minute average delay, 0.8% recent cancellation rate, and 8 available carriers is the concrete summary of what BTS data shows about reliability on this pairing.