Route · IAD → SJU · 2020–2025 BTS data
Washington to San Juan
According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), IAD to SJU (Washington to San Juan) ranks #3673 of 4927 tracked domestic routes by total flights (most flights = #1).
Data updated 2026-06-13
- 82.9%
- On-time
- +3.9 pts
- vs US avg
- 75 min
- Delay when late
- 2,240
- Flights
- #3673 of 4927
- Corpus placement
Cancelled
0.5%
Best Month
Mar 2025 89%
Worst Month
Jul 2025 60%
Distance
1,571 mi
Carriers
3
Monthly Performance
Recent 24 months of route data.
| Period | Flights | Delayed | Cancelled | Diverted | Carriers |
|---|---|---|---|---|---|
| Dec 2025 | 77 | 29 | 0 | 0 | F9,UA |
| Nov 2025 | 73 | 23 | 0 | 0 | UA,F9 |
| Oct 2025 | 44 | 9 | 0 | 0 | UA,F9 |
| Aug 2025 | 50 | 15 | 0 | 0 | F9,UA |
| Jul 2025 | 53 | 21 | 1 | 0 | UA,F9 |
| Jun 2025 | 50 | 13 | 0 | 0 | UA,F9 |
| May 2025 | 38 | 6 | 0 | 0 | UA,F9 |
| Apr 2025 | 38 | 3 | 0 | 0 | UA |
| Mar 2025 | 61 | 7 | 0 | 0 | UA |
| Feb 2025 | 56 | 13 | 0 | 0 | UA |
| Jan 2025 | 62 | 18 | 1 | 0 | UA |
| Dec 2024 | 44 | 12 | 0 | 0 | UA |
| Nov 2024 | 30 | 3 | 0 | 0 | UA |
| Oct 2024 | 31 | 2 | 0 | 0 | UA |
| Aug 2024 | 37 | 9 | 0 | 0 | UA |
| Jul 2024 | 39 | 10 | 0 | 0 | UA |
| Jun 2024 | 40 | 5 | 0 | 0 | UA |
| May 2024 | 33 | 1 | 0 | 0 | UA |
| Apr 2024 | 38 | 1 | 0 | 1 | UA |
| Mar 2024 | 40 | 5 | 0 | 0 | UA |
| Feb 2024 | 33 | 2 | 0 | 0 | UA |
| Jan 2024 | 42 | 9 | 3 | 0 | UA |
| Dec 2023 | 49 | 5 | 0 | 0 | UA |
| Nov 2023 | 30 | 1 | 0 | 1 | UA |
IAD–SJU seasonal on-time pattern
Best: May (92.1%) · weakest: July (71.2%)
Strongest calendar month
May
92.1% on-time · ~33 flights/mo
Busiest calendar month
December
~54 flights/mo avg
Weakest calendar month
July
71.2% on-time · ~41 flights/mo
Cancellation Rate
0.5%
5 of 1,088 flights
Diversion Rate
0.2%
2 of 1,088 flights
Explore origin & destination
On-time and delay data for the airports this route connects.
IAD - Washington
Full on-time, delay-cause, and seasonal performance for Washington, DC.
IAD on-time profileSJU - San Juan
Full on-time, delay-cause, and seasonal performance for San Juan, PR.
SJU on-time profileCompare the two airports
See IAD and SJU side by side on delays, cancellations, and reliability.
Compare IAD vs SJUOrigin-hub reliability standing
Mid-pack among IAD departures
From IAD, this corridor sits with 42 other 75–85% on-time routes out of 58 tracked departures, not the hub's reliability leaders (14 at ≥85%) and not the softest ( 2 below 75%). Destination: San Juan · fleet on-time rank #1989 of 4927.
Similar routes
Other BTS-tracked routes with comparable performance or trip length to IAD–SJU.
Routes with a similar on-time rate
What the Data Says About IAD to SJU
Bureau of Transportation Statistics records show Washington to San Juan (IAD to SJU) running a 82.9% on-time rate over 2,240 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 74.9 minutes. The 1,571-mile corridor is served by 3 carriers, and over the last 24 months 0.5% of 1,088 flights were cancelled, 0.2% diverted.
The monthly split is wide on this route: Mar 2025 posted the strongest performance at 89% on-time, while Jul 2025 came in at just 60% - a 28-point swing worth factoring into travel timing.
On the multi-year calendar, IAD–SJU peaks in May at 92.1% on-time while December carries the heaviest traffic (~54 flights per month) ; the softest month is July at 71.2%, a 20.9-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.
Frequently Asked Questions
Where does IAD to SJU rank among US routes by traffic? ▼
How often are flights delayed from IAD to SJU? ▼
What is the cancellation rate for IAD to SJU? ▼
How far is the flight from IAD to SJU? ▼
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Airports on this route
Data source
Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.
Read our methodology - how this data is sourced, computed, and verified.
Using IAD–SJU data
IAD–SJU runs 3.9 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.
- Compare IAD and SJU airport profiles: delay causes and top routes differ even on the same corridor. IAD airport
- If your dates flex, May (92.1% on-time) beats July (71.2%) on this corridor. Seasonal chart
- 4 other routes post a similar 82.9% on-time rate; compare before you commit to this pairing. Similar routes
On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.
Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.