Carrier route record
UABWI→DEN
United Airlines · Baltimore to Denver
- Flights
- 840
- Period
- September 2025 to August 2026
- Share of route
- 30%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with United Airlines.
United on BWI to DEN earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.3%. When something does go wrong the average delay runs about an hour. That rests on 840 flights, with a median arrival 8 minutes early.
Set against the rest of the country, United's BWI to DEN record is 7 points better than the US average of 77.3%. That gap is worth roughly 72 fewer late arrivals for every thousand flights.
Key figures
On time
84.5%
Arrivals under 15 minutes late, of 832 completed flights
Avg delay
61 min
Across delayed arrivals only, not all flights
Cancelled
0.48%
National rate is 1.89%
Whole route
76.0%
Every carrier on BWI to DEN, 2,784 flights
These figures cover 840 flights between September 2025 and August 2026. The median arrival is 8 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Carrier by carrier
United against every carrier on BWI to DEN
United flew 840 of the 2,784 flights on BWI to DEN, about 30% of it. Its 84.5% on time is 9 points better than the route as a whole, which runs 76.0%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from United at 84.5% to Frontier at 72.0%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines (this page) | 840 | 84.5% | 61 min | 0.48% | B+ |
| Southwest Airlines | 1,919 | 72.2% | 50 min | 1.82% | C |
| Frontier Airlinesthin sample | 25 | 72.0% | 51 min | 0.00% | C+ |
Flight by flight
United flight numbers on BWI to DEN
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Departure window
When United runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 12 points, against half a point between the best and worst carrier.
- 5am–8am2 flights—
- 8am–11am473 flights89.6%
- 11am–2pm—
- 2pm–5pm363 flights77.7%
- 5pm–8pm—
- 8pm–5am2 flights—
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 89.6% of the time, against 77.7% for the afternoon window. That is 12 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 473 flights scheduled in it.
Across the year
United on BWI to DEN through the year
August is the worst month at 70.0% on time, 24 points below October, the best at 93.5%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. October was the busiest month here, with 93 flights.
Across the week, Tuesday is the strongest day at 90.8% on time and Thursday the weakest at 79.7%, a spread of 11 points.
Arrival by arrival
How late United on BWI to DEN runs when it is late
United on BWI to DEN often beats the schedule: 267 of 832 completed flights, 32%, arrived 15 minutes or more early. The 129 late arrivals split 54 under half an hour, 39 between 30 and 60 minutes, and 36 an hour or more.
- 15+ min early267 flights32.1%
- Within 15 min436 flights52.4%
- 15–29 min late54 flights6.5%
- 30–59 min late39 flights4.7%
- 1–2 hours late22 flights2.6%
- 2+ hours late14 flights1.7%
Scale runs 0% to 100%.
Share of 832 completed flights by arrival against schedule.
19 of 90 late departures made up the time and arrived on time, 21% of them. In the other direction, 58 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at DEN.
The worst days
Worst days for United on BWI to DEN
The latest arrival of the period was on 12 June 2026, 11 hours 33 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on four of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 12 June 2026 | 11 hours 33 minutes | Late-arriving aircraft |
| 4 June 2026 | 5 hours 59 minutes | Late-arriving aircraft |
| 18 July 2026 | 5 hours 51 minutes | Late-arriving aircraft |
| 6 March 2026 | 4 hours 25 minutes | Late-arriving aircraft |
| 1 March 2026 | 3 hours 26 minutes | Carrier |
Delay causes
Why United runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,827 reported delay minutes.
- 42%National Airspace System
- 38%Late-arriving aircraft
- 15%Carrier
- 5%Extreme weather
38% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 7,827 reported delay minutes here, that single category outweighs weather by 8 to one. The split is drawn from 7,827 reported delay minutes.
42% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 3,263 minutes out of 7,827, against a national NAS share of 21%.
Cancellations are rare at 0.48%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 4.3% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 1,491 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg runs 82.2% on time across 839 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 840 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking United on BWI to DEN
Put together: treat all of this as provisional. 840 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 84.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 832 completed flights over 12 months sit behind that.
Related
Where to go next
- BWI to DEN, every carrier
- United on DEN to BWI, the return leg
- Southwest Airlines on BWI to DEN72.2%
- United Airlines network-wide record
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- Denver International (DEN) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.