Route reliability record
SFO→RDU
San Francisco to Raleigh
- Flights
- 896
- Period
- July 2025 to June 2026
- Distance
- 2,400 mi
- Carriers
- 1
This route 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 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 896 SFO to RDU flights, with a median arrival 12 minutes early.
Best time to fly SFO to RDU: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 99.2% of the time and Tuesday flights 95.0%, against 89.6% for the route overall.
Set against the rest of the country, this route's record is 12 points better than the US average of 77.6%. That gap is worth roughly 120 fewer late arrivals for every thousand flights.
Key figures
On time
89.6%
Arrivals under 15 minutes late, of 892 completed flights
Avg delay
60 min
Across delayed arrivals only, not all flights
Cancelled
0.22%
National rate is 1.81%
Best carrier
United
89.6% on time across 896 flights
These figures cover 896 flights between July 2025 and June 2026. The median arrival is 12 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
Which airline is most reliable on SFO to RDU
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 | 896 | 89.6% | 60 min | 0.22% | A+ |
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 14 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–8am120 flights99.2%
- 8am–11am163 flights91.4%
- 11am–2pm227 flights91.6%
- 2pm–5pm16 flights—
- 5pm–8pm—
- 8pm–5am370 flights85.6%
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 99.2% of the time, against 85.6% for the overnight window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 370 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 19 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.
June is the worst month at 78.9% on time, 19 points below February, the best at 98.0%. 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. December was the busiest month here, with 87 flights.
Across the week, Tuesday is the strongest day at 95.0% on time and Sunday the weakest at 83.6%. 11 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 47% of the 5,549 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 47%Late-arriving aircraft
- 29%Carrier
- 13%National Airspace System
- 12%Extreme weather
Extreme weather accounts for 12% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 1.9 times the usual weather exposure. The split is drawn from 5,549 reported delay minutes.
47% 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 5,549 reported delay minutes here, that single category outweighs weather by 4 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.
Cancellations are rare at 0.22%, 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 actually costs
Badly late arrivals are rare here: only 3.0% 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 2,400 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 80.5% on time across 895 flights, 9 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 9 points of difference.
One caution: this is a thin sample. 896 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.
Work out the risk of missing a connection in RDU after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 896 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 89.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 892 completed flights over 12 months sit behind that.
Common questions
SFO to RDU questions
How often is SFO to RDU delayed?
About one flight in ten arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 10.4% of the 896 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is SFO to RDU compared with the rest of the country?
89.6% of flights arrive on time here against a national 77.6%, a difference of 12 points in its favour. That is worth a A+ on this site's grading scale.
What time of day has the fewest delays on SFO to RDU?
The 5am–8am departure window is the strongest at 99.2% on time. The 8pm–5am window is the weakest at 85.6%, 14 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 June delays on SFO to RDU?
June is the weakest month at 78.9% on time, compared with 98.0% in February. Across the year that is 19 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
- RDU to SFO — the return legseparate record
- San Francisco International (SFO) delay statistics
- Raleigh-Durham International (RDU) delay statistics
- SFO to LAX, a related route73.9%
- ATL to RDU, a related route80.4%
- SFO to SEA, a related route73.7%
- United Airlines on-time record89.6%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. SFO to RDU and RDU 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.