Flight Reliability
UA 2129 · United Airlines
San Diego → Washington (SAN–IAD)98% of its flights flew this route. The rest (SFO–LAS) are included in these numbers.
93
Nerd Approved
WanderNerd Reliability Score
- 89%
- Arrive within 15 minutes
- 2 min
- Average arrival delay
- 0.9%
- Cancelled
- 13 min early
- Median arrival delay
Based on 331 historical flights. Data through May 2026.
What the data says
Friday is doing you no favors.
UA 2129 arrived on time 96% of the time on Tuesdays. On Fridays: 85%.
Better than the United Airlines network average.
UA 2129 arrived on time 89% of the time, versus 79% across the United Airlines network.
The breakdown
- Mon88%(49 flights)
- Tue96%(44 flights)
- Wed88%(51 flights)
- Thu89%(52 flights)
- Fri85%(52 flights)
- Sat90%(29 flights)
- Sun90%(51 flights)
- 6–9 AM—(5 flights)
- 9 PM–12 AM89%(323 flights)
82%
May
Jun 87% → May 82% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 87% | 30 |
| July 2025 | 81% | 31 |
| August 2025 | 90% | 31 |
| September 2025 | 96% | 28 |
| October 2025 | 96% | 27 |
| November 2025 | 83% | 30 |
| December 2025 | 93% | 29 |
| January 2026 | 85% | 26 |
| February 2026 | 95% | 20 |
| March 2026 | 83% | 23 |
| April 2026 | 100% | 25 |
| May 2026 | 82% | 28 |
- Departures on time
- 88%
- Diverted
- 0%
- Flights flown
- 328
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 331 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.