Route reliability record
SFO→LAS
San Francisco to Las Vegas
- Flights
- 6,140
- Period
- September 2025 to August 2026
- Distance
- 414 mi
- Carriers
- 5
This route sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 6,140 SFO to LAS flights, of which United Airlines flew 2,817 at 76.8% on time.
Best time to fly SFO to LAS: a 5am–8am departure, ideally on a Saturday. Flights in that window arrived on time 95.2% of the time and Saturday flights 81.3%, against 70.2% for the route overall.
United Airlines is the most reliable of the four carriers covered here at 76.8% on time across 2,817 flights.
Key figures
On time
70.2%
Arrivals under 15 minutes late, of 6,091 completed flights
Avg delay
65 min
Across delayed arrivals only, not all flights
Cancelled
0.70%
National rate is 1.89%
Best carrier
United
76.8% on time across 2,817 flights
These figures cover 6,140 flights between September 2025 and August 2026. Beyond the headline rate, 11.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on SFO to LAS
The choice of carrier is not cosmetic here. United Airlines arrives on time 76.8% of the time; Frontier Airlines manages 60.0%. Sample sizes sit next to every figure, because a two-point gap across 906 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 2,817 | 76.8% | 55 min | 0.35% | B+ |
| Alaska Airlines | 1,101 | 72.7% | 63 min | 0.54% | C+ |
| Southwest Airlines | 1,314 | 60.6% | 64 min | 0.84% | D+ |
| Frontier Airlines | 906 | 60.0% | 87 min | 1.77% | D |
| SkyWest Airlinesthin sample | 2 | 50.0% | 81 min | 0.00% | F+ |
The spread between United and Frontier is 17 points, wide enough that it should decide the booking. On a hundred trips that is 17 more arrivals inside the on-time window.
Flight by flight
Flights on SFO to LAS
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 Las Vegas
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. 2 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SJC → LASSan Jose to Las Vegas | Southwest Airlines | 80.2% | 80.6% | 0.49% | 5am–8am, Tue | — |
| 2. SFO → LASSan Francisco to Las Vegas | United Airlines | 76.5% | 76.8% | 0.35% | 5am–8am, Sat | UA 1995 19:10 |
| 3. OAK → LASOakland to Las Vegas | Southwest Airlines | 75.9% | 76.4% | 0.59% | 5am–8am, Sat (route) | — |
| 4. SFO → LASSan Francisco to Las Vegas | Alaska Airlines | 72.3% | 72.7% | 0.54% | 5am–8am, Wed | AS 718 07:25 |
| 5. SFO → LASSan Francisco to Las Vegas | Southwest Airlines | 60.1% | 60.6% | 0.84% | 5am–8am, 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 39 points, against 17 points between the best and worst carrier.
- 5am–8am759 flights95.2%
- 8am–11am1,109 flights78.6%
- 11am–2pm1,045 flights58.2%
- 2pm–5pm986 flights56.4%
- 5pm–8pm1,044 flights72.5%
- 8pm–5am1,197 flights66.3%
Scale runs 50% to 100%.
Book the early departure. Flights leaving between 5am–8am arrive on time 95.2% of the time, against 56.4% for the afternoon window. That is 39 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 1,197 flights scheduled in it.
Explore
Filter SFO to LAS 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 LAS, the best departure window is 5am–8am at 95.2% on time and the worst is 2pm–5pm at 56.4%, a wide gap of 38.8 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am95.2%
- 8–11am78.6%
- 11am–2pm58.2%
- 2–5pm56.4%
- 5–8pm72.5%
- 8pm–5am66.3%
best all US flightsScale 50% to 100%.
Across the year
When delays peak on this route
This route's year swings by 28 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 53.4% on time, 28 points below March, the best at 81.8%. 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 548 flights.
Across the week, Saturday is the strongest day at 81.3% on time and Thursday the weakest at 61.9%, a spread of 19 points.
Delay causes
Why this route gets delayed
Late-arriving aircraft accounts for 58% of the 118,000 delay minutes carriers reported here, and the remaining four split what is left.
- 58%Late-arriving aircraft
- 22%Carrier
- 19%National Airspace System
- 1%Extreme weather
- 0%Security
58% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 118,000 reported delay minutes here, that single category outweighs weather by 54 to one. The split is drawn from 117,929 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 95.2% on time here.
Cancellations are rare at 0.70%, 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
11.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 414 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 58.0% on time across 6,137 flights, 12 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 12 points of difference.
The sample behind these figures is 6,140 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 LAS 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. March runs 81.8% on time and August 53.4%, a swing of 28 points. If the dates move at all, move them out of August before you think about anything else. 6,091 completed flights over 12 months sit behind that.
Common questions
SFO to LAS questions
How often is SFO to LAS delayed?
Roughly one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 29.8% of the 6,140 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on SFO to LAS?
United Airlines leads at 76.8% on time across 2,817 flights. Frontier Airlines is at the other end on 60.0%, a gap of 17 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 LAS?
The 5am–8am departure window is the strongest at 95.2% on time. The 2pm–5pm window is the weakest at 56.4%, 39 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 LAS?
August is the weakest month at 53.4% on time, compared with 81.8% in March. Across the year that is 28 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
- LAS to SFO — the return legseparate record
- San Francisco International (SFO) delay statistics
- Harry Reid International (LAS) delay statistics
- United Airlines on SFO to LAS76.8%
- Alaska Airlines on SFO to LAS72.7%
- Southwest Airlines on SFO to LAS60.6%
- Frontier Airlines on SFO to LAS60.0%
- SFO to LAX, a related route70.9%
- LAX to LAS, a related route75.8%
- SFO to SEA, a related route72.3%
- United Airlines on-time record76.8%
- Alaska Airlines on-time record72.7%
- Southwest Airlines on-time record60.6%
- Same route, different airline: where the carrier you pick matters most
- Why the first flight of the morning is statistically safest
Direction matters. SFO to LAS and LAS 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.