Route reliability record

SFO→LAX

San Francisco to Los Angeles

Flights: 10,834
Period: June 2025 to May 2026
Distance: 337 mi
Carriers: 8

This route sits in the middle of the pack with a B+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.4%. The late ones land about an hour behind schedule. That rests on 10,834 flights, of which United Airlines flew 3,255 at 79.6% on time.

United Airlines is the most reliable of the seven carriers covered here at 79.6% on time across 3,255 flights.

On time

75.8%

Arrivals under 15 minutes late, of 10,738 completed flights

Avg delay

60 min

Across delayed arrivals only, not all flights

Cancelled

0.86%

National rate is 1.80%

Best carrier

United

79.6% on time across 3,255 flights

These figures cover 11,000 flights between June 2025 and May 2026. The median arrival is 4 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 LAX

The choice of carrier is not cosmetic here. United Airlines arrives on time 79.6% of the time; Southwest Airlines manages 64.9%. Sample sizes sit next to every figure, because a two-point gap across 1,325 flights means less than a ten-point one.

On-time performance by carrier on SFO to LAX
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	3,255	79.6%	49 min	0.25%	B+
SkyWest Airlines	2,610	78.6%	59 min	1.07%	B
American Airlines	376	77.3%	105 min	0.27%	B+
Delta Air Lines	2,374	75.2%	66 min	1.56%	B
Alaska Airlines	506	73.0%	48 min	0.99%	C+
Frontier Airlines	387	67.5%	83 min	1.55%	C
Southwest Airlines	1,325	64.9%	60 min	0.60%	D+
Envoy Airthin sample	1	0.0%	35 min	0.00%	F+

The spread between United and Southwest is 15 points, wide enough that it should decide the booking. On a hundred trips that is 15 more arrivals inside the on-time window.

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 28 points, against 15 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,898 flights92.2%
8am–11am2,069 flights81.7%
11am–2pm2,016 flights67.2%
2pm–5pm1,515 flights70.2%
5pm–8pm1,950 flights74.6%
8pm–5am1,386 flights64.6%

Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 64.6% on time, against 92.2% for the 5am–8am 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.

Across the year

When delays peak on this route

This route's year swings by 21 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.January best, May worst

Delays peak in May, when the on-time rate falls to 65.3%. January is the strongest month at 86.0%. Moving a flexible trip across that boundary buys 21 points.

Across the week, Tuesday is the strongest day at 81.0% on time and Thursday the weakest at 71.7%. 9 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 55% of the 157,000 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
55%
Carrier
26%
National Airspace System
18%
Extreme weather
1%
Security
0%

55% 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 157,000 reported delay minutes here, that single category outweighs weather by 55 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 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 are rare at 0.86%, below the national 1.80% 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

7.5% of arrivals land an hour or more late, close to the national 8.2%. 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 about an hour kind, which a normal layover absorbs.

At 337 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 67.8% on time across 10,832 flights, 8 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 8 points of difference.

The sample behind these figures is 10,834 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.

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 86.0% on time and May 65.3%, a swing of 21 points. If the dates move at all, move them out of May before you think about anything else.

Common questions

SFO to LAX questions

How often is SFO to LAX delayed?

About 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 24.2% of the 10,834 flights in this analysis, against 22.6% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on SFO to LAX?

United Airlines leads at 79.6% on time across 3,255 flights. Southwest Airlines is at the other end on 64.9%, a gap of 15 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 SFO to LAX?

The 5am–8am departure window is the strongest at 92.2% on time. The 8pm–5am window is the weakest at 64.6%, 28 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 May delays on SFO to LAX?

May is the weakest month at 65.3% on time, compared with 86.0% in January. Across the year that is 21 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

Direction matters. SFO to LAX and LAX to SFO are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

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

Key figures