Route Reliability
Washington → San Juan
IAD–SJU · 1,572 miles · Washington Dulles International Airport to Luis Muñoz Marín International Airport
- 76%
- Arrive within 15 minutes
- 18 min
- Average arrival delay
- 0.7%
- Cancelled
- 688
- Flights in the data
Data through May 2026.
Who flies it best
Ranked by on-time arrivals. Historical results, not predictions.
- 1.United Airlines81%588 flights
- 2.Frontier Airlines44%100 flights
What the data says
Morning-you made the right choice.
IAD–SJU flights departing between 6–9 AM arrived on time 88% of the time, versus 24% between 12–3 PM.
Sunday scaries are real for this one.
IAD–SJU flights arrived on time 90% of the time on Wednesdays and just 68% on Sundays. That gap is worth planning around.
United Airlines has a clear lead on this route.
United Airlines arrived on time 81% of the time on this route; Frontier Airlines managed 44%.
Trending in the right direction.
IAD–SJU flights arrived on time 88% of the time over the last three months in the data, compared with 74% in the three months before that.
Best historical flights
Ranked by on-time arrivals, minimum 100 flights. Past performance, not a promise.
Top flights by on-time rate
More flights on this route
The breakdown
- Mon77%(90 flights)
- Tue75%(91 flights)
- Wed90%(78 flights)
- Thu73%(102 flights)
- Fri84%(90 flights)
- Sat72%(110 flights)
- Sun68%(121 flights)
- 6–9 AM88%(345 flights)
- 9 AM–12 PM71%(14 flights)
- 12–3 PM24%(33 flights)
- 3–6 PM72%(240 flights)
- 6–9 PM48%(44 flights)
- 9 PM–12 AM—(6 flights)
Jun 74% → May 94% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 74% | 50 |
| July 2025 | 60% | 52 |
| August 2025 | 70% | 50 |
| September 2025 | 77% | 13 |
| October 2025 | 80% | 44 |
| November 2025 | 69% | 73 |
| December 2025 | 64% | 77 |
| January 2026 | 83% | 70 |
| February 2026 | 75% | 63 |
| March 2026 | 80% | 66 |
| April 2026 | 89% | 62 |
| May 2026 | 94% | 62 |
Same trip, other airports
Keep nerding
Based on 688 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.