Flight Reliability
UA 4321 · United Airlines
Washington → Albany (IAD–ALB)
76
Usually Fine
WanderNerd Reliability Score
- 79%
- Arrive within 15 minutes
- 19 min
- Average arrival delay
- 1.4%
- Cancelled
- 7 min early
- Median arrival delay
Based on 363 historical flights. Data through May 2026.
What the data says
Friday is doing you no favors.
UA 4321 arrived on time 90% of the time on Thursdays and just 68% on Fridays. That gap is worth planning around.
Ticking up lately.
UA 4321 arrived on time 83% of the time over the last three months in the data, compared with 77% in the three months before that.
The breakdown
- Mon78%(50 flights)
- Tue81%(52 flights)
- Wed83%(52 flights)
- Thu90%(51 flights)
- Fri68%(50 flights)
- Sat84%(51 flights)
- Sun69%(51 flights)
81%
May
Jun 57% → May 81% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 57% | 30 |
| July 2025 | 55% | 29 |
| August 2025 | 90% | 31 |
| September 2025 | 93% | 30 |
| October 2025 | 94% | 31 |
| November 2025 | 76% | 29 |
| December 2025 | 73% | 30 |
| January 2026 | 83% | 30 |
| February 2026 | 74% | 27 |
| March 2026 | 79% | 29 |
| April 2026 | 90% | 30 |
| May 2026 | 81% | 31 |
- Departures on time
- 79%
- Diverted
- 0.3%
- Flights flown
- 357
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 363 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.