Flight Reliability
UA 4831 · United Airlines
Washington → ROA (IAD–ROA)99% of its flights flew this route. The rest (PVD–IAD) are included in these numbers.
84
Pretty Reliable
WanderNerd Reliability Score
- 79%
- Arrive within 15 minutes
- 13 min
- Average arrival delay
- 0.3%
- Cancelled
- 4 min early
- Median arrival delay
Based on 323 historical flights. Data through May 2026.
What the data says
Friday is doing you no favors.
UA 4831 arrived on time 85% of the time on Wednesdays. On Fridays: 70%.
It basically never cancels.
Out of 323 scheduled flights, only 0.3% were cancelled.
Recent months have been rougher.
UA 4831 arrived on time 73% of the time over the last three months in the data, compared with 83% in the three months before that.
The breakdown
- Mon73%(51 flights)
- Tue83%(52 flights)
- Wed85%(52 flights)
- Thu79%(52 flights)
- Fri70%(47 flights)
- Sat83%(29 flights)
- Sun80%(39 flights)
65%
May
Jun 48% → May 65% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 48% | 21 |
| July 2025 | 78% | 23 |
| August 2025 | 65% | 20 |
| September 2025 | 100% | 24 |
| October 2025 | 87% | 31 |
| November 2025 | 90% | 30 |
| December 2025 | 74% | 31 |
| January 2026 | 80% | 30 |
| February 2026 | 96% | 24 |
| March 2026 | 67% | 27 |
| April 2026 | 87% | 30 |
| May 2026 | 65% | 31 |
- Departures on time
- 78%
- Diverted
- 0%
- Flights flown
- 322
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 323 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.