Route reliability record
SFO→IAD
San Francisco to Washington
- Flights
- 2,690
- Period
- September 2025 to August 2026
- Distance
- 2,418 mi
- Carriers
- 1
This route lands a B+, 6 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 2,690 SFO to IAD flights, with a median arrival 10 minutes early.
Best time to fly SFO to IAD: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 98.4% of the time and Tuesday flights 86.7%, against 83.0% for the route overall.
Set against the rest of the country, this route's record is 6 points better than the US average of 77.3%. That gap is worth roughly 57 fewer late arrivals for every thousand flights.
Key figures
On time
83.0%
Arrivals under 15 minutes late, of 2,670 completed flights
Avg delay
58 min
Across delayed arrivals only, not all flights
Cancelled
0.63%
National rate is 1.89%
Best carrier
United
83.0% on time across 2,690 flights
These figures cover 2,690 flights between September 2025 and August 2026. The median arrival is 10 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.
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Carrier by carrier
Which airline is most reliable on SFO to IAD
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 | 2,690 | 83.0% | 58 min | 0.63% | B+ |
Flight by flight
Flights on SFO to IAD
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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Best ways to make this trip
The most reliable ways to fly San Francisco to Washington
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 3 of the top 4 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SFO → BWISan Francisco to Baltimore | United Airlines | 90.4% | 90.8% | 0.45% | 8am–11am, Tue | UA 2664 09:09 |
| 2. SFO → IADSan Francisco to Washington | United Airlines | 82.5% | 83.0% | 0.63% | 5am–8am, Tue | UA 1453 16:55 |
| 3. SFO → DCASan Francisco to Washington | United Airlines | 78.0% | 78.4% | 0.55% | 8am–11am, Sat | UA 1678 08:20 |
| 4. SFO → BWISan Francisco to Baltimore | Southwest Airlines | 62.5% | 63.0% | 0.82% | 8pm–5am, Tue | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 21 points, against half a point between the best and worst carrier.
- 5am–8am126 flights98.4%
- 8am–11am576 flights80.4%
- 11am–2pm519 flights77.9%
- 2pm–5pm287 flights81.1%
- 5pm–8pm128 flights85.2%
- 8pm–5am1,054 flights85.2%
Scale runs 70% to 100%.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 77.9% on time against 98.4% for 5am–8am. 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 8pm–5am window is the busiest, with 1,054 flights scheduled in it.
Explore
Filter SFO to IAD by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On SFO to IAD, the best departure window is 5am–8am at 98.4% on time and the worst is 11am–2pm at 77.9%, a wide gap of 20.5 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am98.4%
- 8–11am80.4%
- 11am–2pm77.9%
- 2–5pm81.1%
- 5–8pm85.2%
- 8pm–5am85.2%
best all US flightsScale 60% to 100%.
Across the year
When delays peak on this route
This route's year swings by 23 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
August is the worst month at 68.9% on time, 23 points below February, the best at 92.1%. 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. May was the busiest month here, with 268 flights.
Across the week, Tuesday is the strongest day at 86.7% on time and Monday the weakest at 79.7%, a spread of 7 points.
Delay causes
Why this route gets delayed
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 26,000 reported delay minutes.
- 42%Late-arriving aircraft
- 40%Carrier
- 18%National Airspace System
- 0%Extreme weather
42% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 26,000 reported delay minutes here, that single category outweighs weather by 42 to one. The split is drawn from 26,415 reported delay minutes.
The largest share of delay minutes, 40%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 10,000 of the 26,000 delay minutes reported here.
Cancellations are rare at 0.63%, 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 actually costs
5.1% of arrivals land an hour or more late, close to the national 8.3%, so 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 2,418 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 77.5% on time across 2,688 flights, 6 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 6 points of difference.
The sample behind these figures is 2,690 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in IAD after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 92.1% on time and August 68.9%, a swing of 23 points. If the dates move at all, move them out of August before you think about anything else. 2,670 completed flights over 12 months sit behind that.
Common questions
SFO to IAD questions
How often is SFO to IAD delayed?
About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 17.0% of the 2,690 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
How reliable is SFO to IAD compared with the rest of the country?
83.0% of flights arrive on time here against a national 77.3%, a difference of 6 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on SFO to IAD?
The 5am–8am departure window is the strongest at 98.4% on time. The 11am–2pm window is the weakest at 77.9%, 21 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are August delays on SFO to IAD?
August is the weakest month at 68.9% on time, compared with 92.1% in February. Across the year that is 23 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- IAD to SFO — the return legseparate record
- San Francisco International (SFO) delay statistics
- Washington Dulles International (IAD) delay statistics
- SFO to LAX, a related route70.9%
- ATL to IAD, a related route76.4%
- SFO to SEA, a related route72.3%
- United Airlines on-time record83.0%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. SFO to IAD and IAD to SFO are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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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.