Flight Reliability
UA 1556 · United Airlines
Newark → San Juan (EWR–SJU)
81
Pretty Reliable
WanderNerd Reliability Score
- 78%
- Arrive within 15 minutes
- 4 min
- Average arrival delay
- 1.4%
- Cancelled
- 5 min early
- Median arrival delay
Based on 365 historical flights. Data through May 2026.
What the data says
Thursdays have been rough.
UA 1556 arrived on time 85% of the time on Sundays and just 69% on Thursdays. That gap is worth planning around.
Better than the EWR–SJU route average.
UA 1556 arrived on time 78% of the time, versus 71% across the EWR–SJU route.
Ticking up lately.
UA 1556 arrived on time 85% of the time over the last three months in the data, compared with 78% in the three months before that.
The breakdown
- Mon78%(50 flights)
- Tue80%(51 flights)
- Wed79%(52 flights)
- Thu69%(52 flights)
- Fri77%(52 flights)
- Sat80%(51 flights)
- Sun85%(52 flights)
87%
May
Jun 87% → May 87% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 87% | 30 |
| July 2025 | 84% | 31 |
| August 2025 | 81% | 31 |
| September 2025 | 90% | 30 |
| October 2025 | 48% | 31 |
| November 2025 | 63% | 30 |
| December 2025 | 77% | 31 |
| January 2026 | 68% | 28 |
| February 2026 | 89% | 26 |
| March 2026 | 71% | 31 |
| April 2026 | 97% | 30 |
| May 2026 | 87% | 31 |
- Departures on time
- 87%
- Diverted
- 0%
- Flights flown
- 360
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 365 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.