Carrier route record
UABWI→SFO
United Airlines · Baltimore to San Francisco
- Flights
- 721
- Period
- July 2025 to June 2026
- Share of route
- 66%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with United Airlines.
United on BWI to SFO lands a B+, level with the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 721 flights, with a median arrival 6 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate United on BWI to SFO from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.3%
Arrivals under 15 minutes late, of 713 completed flights
Avg delay
56 min
Across delayed arrivals only, not all flights
Cancelled
0.83%
National rate is 1.81%
Whole route
71.2%
Every carrier on BWI to SFO, 1,086 flights
These figures cover 721 flights between July 2025 and June 2026. The median arrival is 6 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.
Carrier by carrier
United against every carrier on BWI to SFO
United flew 721 of the 1,086 flights on BWI to SFO, most of the route. Its 78.3% on time is 7 points better than the route as a whole, which runs 71.2%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 78.3% to Southwest at 57.2%.
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) | 721 | 78.3% | 56 min | 0.83% | B+ |
| Southwest Airlines | 365 | 57.2% | 57 min | 0.82% | D+ |
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 25 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am189 flights88.2%
- 8am–11am236 flights88.4%
- 11am–2pm—
- 2pm–5pm—
- 5pm–8pm296 flights63.8%
- 8pm–5am—
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 63.8% on time, against 88.4% for the 8am–11am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5pm–8pm window is the busiest, with 296 flights scheduled in it.
Across the year
United on BWI to SFO through the year
June is the worst month at 58.5% on time, 34 points below October, the best at 92.0%. 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. July was the busiest month here, with 84 flights.
Across the week, Saturday is the strongest day at 85.3% on time and Wednesday the weakest at 75.3%. 10 points is a smaller lever than departure hour, but it is free.
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 8,677 reported delay minutes.
- 42%National Airspace System
- 31%Late-arriving aircraft
- 20%Carrier
- 8%Extreme weather
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 3,601 minutes out of 8,677, against a national NAS share of 21%. The split is drawn from 8,677 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 88.4% on time here.
Cancellations are rare at 0.83%, below the national 1.81% 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
6.2% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
At 2,457 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 88.7% on time across 720 flights, 10 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 10 points of difference.
One caution: this is a thin sample. 721 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 SFO
Put together: treat all of this as provisional. 721 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 78.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 713 completed flights over 12 months sit behind that.
Related
Where to go next
- BWI to SFO, every carrier
- United on SFO to BWI, the return leg
- Southwest Airlines on BWI to SFO57.2%
- United Airlines network-wide record
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- San Francisco International (SFO) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.