Flight Reliability
UA 4791 · United Airlines
Chicago → SBN (ORD–SBN)
61
A Little Dicey
WanderNerd Reliability Score
- 70%
- Arrive within 15 minutes
- 21 min
- Average arrival delay
- 2.8%
- Cancelled
- 3 min early
- Median arrival delay
Based on 361 historical flights. Data through May 2026.
What the data says
Saturdays have been rough.
UA 4791 arrived on time 88% of the time on Thursdays and just 58% on Saturdays. That gap is worth planning around.
A bit ahead of the ORD–SBN route.
UA 4791 arrived on time 70% of the time, versus 63% across the ORD–SBN route.
Lagging the United Airlines network.
UA 4791 arrived on time 70% of the time, versus 79% across the United Airlines network.
Ticking up lately.
UA 4791 arrived on time 63% of the time over the last three months in the data, compared with 59% in the three months before that.
The breakdown
- Mon60%(50 flights)
- Tue73%(52 flights)
- Wed68%(50 flights)
- Thu88%(49 flights)
- Fri76%(50 flights)
- Sat58%(50 flights)
- Sun64%(50 flights)
77%
May
Jun 73% → May 77% on time
| Month | On-time percentage | Flights |
|---|---|---|
| June 2025 | 73% | 30 |
| July 2025 | 70% | 30 |
| August 2025 | 87% | 31 |
| September 2025 | 86% | 29 |
| October 2025 | 90% | 30 |
| November 2025 | 57% | 28 |
| December 2025 | 52% | 29 |
| January 2026 | 59% | 29 |
| February 2026 | 67% | 27 |
| March 2026 | 54% | 28 |
| April 2026 | 59% | 29 |
| May 2026 | 77% | 31 |
- Departures on time
- 77%
- Diverted
- 0%
- Flights flown
- 351
- Months covered
- 12
Same route, other flights
Keep nerding
Based on 361 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.