Route profile
SJU→IAD
Flight reliability, delays and best times to fly from San Juan to Washington, 1,571 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 90% of comparable major US routes (4,598 compared)
Calculated from 1,683 flights. How this is calculated
SJU → IAD arrives on time 85.8% of the time; the return trip, IAD → SJU, arrives on time 80.1% of the time, a 5.7-point gap between the two directions of the same city pair.
SJU → IAD spends 23.1 minutes on the ground on a 1,571-mile trip: 16.0 minutes from pushback to wheels-up at SJU and 7.1 minutes from touchdown to gate at IAD.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
When it goes wrong
July 2023 – July 2026
26 min late
against a median of 9 min early
Percentiles over 1,683 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at IAD after arriving from SJU.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 29% | High risk |
| 45 min | 14% | Some risk |
| 60 min | 8.2% | Some risk |
| 90 min | 3.7% | Low risk |
| 120 min | 2.5% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.71% of the time and diverts 0.24% of the time, which a late arrival never shows up in.
Chance of missing is the share of 1,667 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 26 minutes late (90th-percentile gate arrival delay), over 1,683 operations.
Any other layover length: connection checker.
Why SJU → IAD runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for SJU → IAD. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on SJU → IAD, at 51.1%: flights here mostly leave late because the plane came in late.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| United Airlines | 1,579 | 87.0% | 0.70% | -9 min | 3.4% |
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Saturday the least, a gap of 9.6 percentage points.
By month
- Jan: 84.6%
- Feb: 86.2%
- Mar: 79.5%
- Apr: 92.0%
- May: 86.5%
- Jun: 86.5%
- Jul: 86.7%
- Aug: 80.2%
- Sep to Oct: no data
- Nov: 87.2%
- Dec: 83.3%
March is historically the weakest month and April the strongest, a spread of 12.5 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 87.2% against 84.0% in the 12 months before — improving by 3.2 percentage points.
Data and methodology
Calculated by FlyerIntel from 1,683 SJU → IAD flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed