San Francisco, CA · departure reliability

SFO

San Francisco International

Departures: 146,683
Period: July 2025 to June 2026
Carriers: 9
US rank: #11 by volume

Terminal building and aircraft stands at a US airport

San Francisco

San Francisco International lands a B, level with the national rate of 77.6%. Roughly one flight in four arrive 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 146,683 flights, of which United Airlines flew 60,681 at 81.1% on time.

United Airlines is the most reliable of the nine carriers covered here at 81.1% on time across 60,681 flights.

On time

77.3%

Departures arriving under 15 minutes late at their destination

Avg delay

68 min

Across delayed flights only

Cancelled

1.00%

National rate is 1.81%

Best carrier

United

81.1% on time here

These figures cover 147,000 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

Which airlines run best out of SFO

The choice of carrier is not cosmetic here. United Airlines arrives on time 81.1% of the time; Southwest Airlines manages 59.0%. Sample sizes sit next to every figure, because a two-point gap across 9,408 flights means less than a ten-point one.

On-time performance by carrier departing SFO
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	60,681	81.1%	59 min	0.55%	B+
SkyWest Airlines	32,078	76.3%	74 min	1.26%	B
Delta Air Lines	13,817	78.7%	68 min	1.19%	B
American Airlines	11,833	77.9%	106 min	1.88%	B
Alaska Airlines	10,554	76.3%	55 min	1.07%	B
Southwest Airlines	9,408	59.0%	59 min	0.82%	D+
JetBlue Airways	4,397	78.6%	75 min	1.61%	B
Frontier Airlines	3,407	65.2%	83 min	1.97%	C
Hawaiian Airlines	507	75.1%	67 min	1.97%	B

The spread between United and Southwest is 22 points, wide enough that it should decide the booking. On a hundred trips that is 22 more arrivals inside the on-time window.

Route by route

Busiest routes out of SFO

Route-level records vary far more than the airport average. These are the 25 busiest departures from SFO, each with its own on-time rate against the airport-wide 77.3%.

Busiest routes from SFO by flight volume
Route	Flights	On time	Avg delay	Cancelled	Grade
SFO to LAX · Los Angeles	11,015	73.9%	60 min	0.84%	C+
SFO to SEA · Seattle	6,770	73.7%	56 min	1.18%	C
SFO to JFK · New York	6,729	80.1%	78 min	1.98%	B
SFO to SAN · San Diego	6,548	66.6%	59 min	1.13%	C
SFO to LAS · Las Vegas	6,066	74.1%	67 min	0.61%	C+
SFO to ORD · Chicago	5,628	76.5%	85 min	1.30%	B
SFO to DEN · Denver	5,410	75.5%	59 min	0.46%	B+
SFO to SNA · Santa Ana	4,726	80.3%	60 min	1.18%	B
SFO to BOS · Boston	4,674	76.9%	74 min	1.35%	B
SFO to PHX · Phoenix	4,643	74.4%	75 min	0.78%	C+
SFO to EWR · Newark	4,401	76.4%	80 min	2.04%	B
SFO to DFW · Dallas-Fort Worth	4,127	73.5%	88 min	2.37%	C
SFO to IAH · Houston	3,600	84.8%	53 min	0.28%	B+
SFO to PDX · Portland	3,514	80.4%	59 min	0.34%	B+
SFO to SLC · Salt Lake City	3,471	77.2%	70 min	0.89%	B+
SFO to ATL · Atlanta	3,350	81.6%	67 min	0.81%	B+
SFO to BUR · Burbank	3,036	77.0%	63 min	1.05%	B
SFO to AUS · Austin	2,792	74.8%	61 min	0.79%	C+
SFO to IAD · Washington	2,788	82.5%	64 min	0.75%	B+
SFO to PSP · Palm Springs	2,504	76.7%	76 min	1.04%	B
SFO to HNL · Honolulu	2,426	81.4%	64 min	0.95%	B+
SFO to PHL · Philadelphia	1,992	85.4%	89 min	1.41%	A
SFO to MSP · Minneapolis	1,919	82.5%	62 min	0.73%	B+
SFO to RNO · Reno	1,897	75.5%	66 min	1.11%	B
SFO to DTW · Detroit	1,797	79.4%	53 min	0.83%	B+

Departure window

The best time of day to leave SFO

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 22 points, against 22 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am18,366 flights92.2%
8am–11am33,022 flights80.4%
11am–2pm26,211 flights70.7%
2pm–5pm23,432 flights71.2%
5pm–8pm17,225 flights76.8%
8pm–5am28,427 flights75.6%

Scale runs 60% to 100%. 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 70.7% on time against 92.2% 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 8am–11am window is the busiest, with 33,022 flights scheduled in it.

Across the year

When SFO runs late

SFO's year swings by 17 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.

Darker means more delays. Figures are on-time percentages.March best, June worst

June is the worst month at 67.1% on time, 17 points below March, the best at 84.0%. 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. June was the busiest month here, with 13,415 flights.

Across the week, Saturday is the strongest day at 82.0% on time and Monday the weakest at 74.6%. 7 points is a smaller lever than departure hour, but it is free.

Delay causes

Why SFO gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 2.23 million 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.

Late-arriving aircraft
44%
Carrier
30%
National Airspace System
22%
Extreme weather
3%
Security
0%

44% 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 2.23 million reported delay minutes here, that single category outweighs weather by 14 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 2,230,896 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 92.2% on time here.

Cancellations sit at 1.00% against a national 1.81%, which is ordinary. Diversions add another 0.31%.

7.7% 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 are the a little over an hour kind, which a normal layover absorbs.

146,683 flights sit behind these numbers, which is a large enough sample that the headline rate is not moving on noise. Where a sub-group falls below 30 flights the site shows a dash instead of a percentage.

What to do with this

Flying out of SFO

Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 84.0% on time and June 67.1%, a swing of 17 points. If the dates move at all, move them out of June before you think about anything else. 144,770 completed flights over 12 months sit behind that.

Common questions

SFO delay questions

How often is San Francisco (SFO) delayed?

Roughly one flight in four arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 22.7% of the 146,683 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

Which airline is most reliable on San Francisco (SFO)?

United Airlines leads at 81.1% on time across 60,681 flights. Southwest Airlines is at the other end on 59.0%, a gap of 22 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on San Francisco (SFO)?

The 5am–8am departure window is the strongest at 92.2% on time. The 11am–2pm window is the weakest at 70.7%, 22 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 San Francisco (SFO)?

June is the weakest month at 67.1% on time, compared with 84.0% in March. Across the year that is 17 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures