Flight profile · United Airlines
UA377
Denver (DEN) to Chicago (ORD) · scheduled 8:30 PM – 11:59 PM
How UA377 performs
1,002 operations, July 2023 – August 2026.
Between its first and last recorded date on DEN → ORD, UA377 averaged about 6 operations a week (1,002 in 1,158 days, cancelled ones included).
UA377 arrived on time 75.7% of the time, against 73.8% for all DEN → ORD flights, so this departure is 1.9 percentage points better than the route as a whole. Against United Airlines’ own flights on this route it is 1.3 points better.
Source: US DOT Bureau of Transportation Statistics · 1,002 operations, July 2023 – August 2026 · If UA377 is cancelled or significantly changed, DOT’s automatic refund rule may entitle you to your money back. The refund checker walks through eligibility.
Where UA377 is right now
A live reading, only if you ask for it. It is not part of the reliability record above.
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Against the rest of the route
| Flight or route | On time | Cancelled | Median delay | Severe | Flights |
|---|---|---|---|---|---|
| UA377 | 75.7% | 0.70% | -8 min | 9.8% | 1,002 |
| United Airlines on DEN → ORD | 74.4% | 0.92% | -2 min | 9.6% | 11,559 |
| All DEN → ORD flights | 73.8% | 1.02% | -3 min | 9.9% | 20,053 |
UA377 cancelled 7 of 1,002 operations (0.70%), close to the 1.02% for DEN → ORD.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – August 2026
Why UA377 runs late
Where US DOT attributed the delay minutes on this flight.
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for UA377 on DEN → ORD. Only delays of 15 minutes or more are attributed. What the five causes mean
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – August 2026
Does a late aircraft delay this flight?
How often the plane that flies UA377 comes in late, and what that does to the departure.
When the aircraft came in 15 or more minutes late, UA377 pushed back an average of 38 minutes late; when it came in on time or early, an average of 7 minutes late.
Matched by tail number to the aircraft’s previous flight into DEN: 909 of 995 departures. Unknown, cancelled or diverted inbounds and gaps over 12 hours are left out.
Against the network at the same turn length
| Share of departures | Inbound landed 15+ late | Left 15+ late after a late inbound | Left 15+ late after an on-time inbound |
|---|---|---|---|
| UA377 | 22% | 57% | 15% |
| Network, same turn | 17% | 69% | 9% |
89 scheduled minutes is enough to clean and board when the aircraft is on time, with little to spare when it is not.
The network row is every flight with a scheduled turn of 60 to 89 minutes. How often UA377’s aircraft landed 15 or more minutes late is higher than the network’s and, once the aircraft was late, how often UA377 left 15 or more minutes late is lower than the network’s.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – August 2026
From pushback to gate
When it leaves DEN late, does that still matter by the time it reaches ORD?
UA377 pushes back an average of 17.7 minutes late and reaches the gate at ORD an average of 7.8 minutes late. The 9.9 minutes between those two figures are slack the published schedule already carries, so a late pushback is partly, not fully, made up before the gate. It spends 19.4 minutes on the taxiways at DEN, 1.0 minutes longer than a typical DEN departure in the same hour.
On arrival at ORD, UA377 spends 8.4 min taxiing from touchdown to the gate — ground time a connecting passenger sits through before they can even leave the aircraft, on top of however late the flight itself ran. That is 9.6 minutes shorter than a typical ORD arrival (18.0 min).
Taxi-out is gate to wheels up and sits inside the scheduled block; the hourly comparison is 58,592 DEN departures. Taxi-in is landing to gate, set against 985,848 arrivals at ORD. More on taxi time.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – August 2026
The hour it leaves DEN
UA377 has one departure time, 8:30 PM, so this is what that hour at DEN is worth.
On-time arrival rate. 58,592 departures from DEN are scheduled in the 8 PM–9 PM hour over the period, against 991,655 across the whole day.
UA377 is scheduled out of DEN at 8:30 PM, in the 8 PM–9 PM bank. Departures from DEN in that hour arrive on time 67.5% of the time against 75.8% across the airport’s whole day — the slot alone is worth 8.2 points worse before anything about this particular flight is considered.
Both airport figures cover every destination from DEN, so they describe the slot, not this journey; the route comparison is above. Why the hour matters.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – August 2026 · Hours below 120 departures are not scored.
By day of week
Does UA377 run worse on particular days?
Wednesday is historically the most reliable day and Thursday the least, a gap of 14.0 percentage points.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – August 2026 · Days with fewer than 120 operations are not scored.
Other routes UA377 has flown
Carriers reassign flight numbers. UA377 also served these 16 other city pairs in the period.
| Route | Operated | Flights | On time |
|---|---|---|---|
| IND→DEN Indianapolis to Denver | March 29, 2026 – August 31, 2026 | 115 | 80.0% |
| ORD→DEN Chicago to Denver | July 1, 2026 – August 10, 2026 | 40 | — |
| EWR→DTW Newark to Detroit | July 4, 2026 | 1 | — |
| PHX→DEN Phoenix to Denver | March 5–28, 2026 | 24 | — |
| PSP→DEN Palm Springs to Denver | December 2, 2025 – March 4, 2026 | 37 | — |
| MSN→DEN Madison to Denver | January 6, 2026 – February 11, 2026 | 37 | — |
| SFO→DEN San Francisco to Denver | October 26, 2025 – December 1, 2025 | 37 | — |
| SLC→DEN Salt Lake City to Denver | September 26, 2025 – October 25, 2025 | 30 | — |
| IAH→XNA Houston to Fayetteville/Springdale/Rogers | July 4, 2025 | 1 | — |
| SNA→DEN Santa Ana to Denver | May 22, 2025 – June 25, 2025 | 35 | — |
| MIA→IAH Miami to Houston | April 6–27, 2025 | 4 | — |
| IAD→BOS Washington to Boston | April 4–25, 2025 | 4 | — |
| RSW→DEN Fort Myers to Denver | March 30, 2025 | 1 | — |
| SMF→DEN Sacramento to Denver | March 6–29, 2025 | 24 | — |
| ORD→CHS Chicago to Charleston | November 28, 2024 | 1 | — |
| FLL→CLE Fort Lauderdale to Cleveland | November 23, 2023 | 1 | — |
The figures above describe only DEN → ORD, the route UA377 flies now.
When it goes wrong
The average describes a usual day. This is the day that ruins a connection.
58 min late
against a median of 8 min early
UA377 has an average that understates its risk: a typical arrival is 8 min early, but the worst tenth are 66 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.
Percentiles over 1,002 operations; cancelled and diverted flights are counted separately.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – August 2026
Other flights on this route
Same airports, same journey, different odds of arriving on time.
| Flight | Airline | On time | Median arrival | Operations |
|---|---|---|---|---|
| AA2771 | American Airlines | 87.4% | 13 min early | 1,084 |
| UA2329 | United Airlines | 81.4% | 2 min early | 1,047 |
| UA377 this flight | United Airlines | 75.7% | 8 min early | 1,002 |
| UA617 | United Airlines | 75.0% | 0 min early | 1,108 |
| UA1898 | United Airlines | 61.9% | 3 min late | 714 |
Among all 5 departures on this route with at least 600 operations, UA377 has the 3rd highest on-time rate, 11.7 points behind the best. Every departure here has at least 600 operations; the other rows are the most punctual on the route, not all of them.
Data and methodology
Calculated by FlyerIntel from 1,002 records of UA377 operating DEN → ORD, published by the US DOT Bureau of Transportation Statistics. A flight counts as delayed when it arrives 15 or more minutes after schedule; cancelled and diverted flights are reported separately, not in the on-time rate.
Full methodology · Data sources · Report a problem
Related research: Most and Least Reliable Flight Numbers · The Delay You Inherit · Making Up Time in the Air
Analysis last recomputed