Carrier route record
UASFO→BWI
United Airlines · San Francisco to Baltimore
- Flights
- 720
- 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 SFO to BWI earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 11 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 50 minutes. That rests on 720 flights, with a median arrival 9 minutes early.
Set against the rest of the country, United's SFO to BWI record is 11 points better than the US average of 77.6%. That gap is worth roughly 111 fewer late arrivals for every thousand flights.
Key figures
On time
88.7%
Arrivals under 15 minutes late, of 711 completed flights
Avg delay
49 min
Across delayed arrivals only, not all flights
Cancelled
0.42%
National rate is 1.81%
Whole route
81.0%
Every carrier on SFO to BWI, 1,085 flights
These figures cover 720 flights between July 2025 and June 2026. The median arrival is 9 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 SFO to BWI
United flew 720 of the 1,085 flights on SFO to BWI, most of the route. Its 88.7% on time is 8 points better than the route as a whole, which runs 81.0%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from United at 88.7% to Southwest at 65.7%.
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) | 720 | 88.7% | 49 min | 0.42% | A+ |
| Southwest Airlines | 365 | 65.7% | 47 min | 0.82% | C+ |
Flight by flight
United flight numbers on SFO to BWI
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. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am346 flights89.3%
- 11am–2pm36 flights77.8%
- 2pm–5pm—
- 5pm–8pm—
- 8pm–5am338 flights89.3%
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 77.8% on time against 89.3% for 8am–11am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8am–11am window is the busiest, with 346 flights scheduled in it.
Across the year
United on SFO to BWI through the year
July is the worst month at 79.7% on time, 17 points below May, the best at 96.4%. 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, Sunday is the strongest day at 91.0% on time and Friday the weakest at 86.0%. 5 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 3,925 reported delay minutes.
- 40%Late-arriving aircraft
- 40%Carrier
- 17%National Airspace System
- 3%Extreme weather
40% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 3,925 reported delay minutes here, that single category outweighs weather by 12 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 3,925 reported delay minutes.
The largest share of delay minutes, 40%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 1,562 of the 3,925 delay minutes reported here.
Cancellations are rare at 0.42%, 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
Badly late arrivals are rare here: only 2.3% land an hour or more behind schedule, against 8.1% 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.
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 78.3% on time across 721 flights, 10 points below 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. 720 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 SFO to BWI
Put together: treat all of this as provisional. 720 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 88.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 711 completed flights over 12 months sit behind that.
Related
Where to go next
- SFO to BWI, every carrier
- United on BWI to SFO, the return leg
- Southwest Airlines on SFO to BWI65.7%
- United Airlines network-wide record
- San Francisco International (SFO) delay statistics
- Baltimore/Washington International Thurgood Marshall (BWI) delay statistics
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
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.