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DelayAtlas

Carrier route record

F9SFOLAS

Frontier Airlines · San Francisco to Las Vegas

Flights
879
Period
July 2025 to June 2026
Share of route
14%
Carriers
5
CGRADE

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Frontier Airlines.

Frontier on SFO to LAS draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 879 flights. The strongest carrier on the route with a full sample, United Airlines, flew 2,757 at 79.6% on time.

United Airlines is the most reliable of the three carriers covered here at 79.6% on time across 2,757 flights.

Key figures

On time

65.6%

Arrivals under 15 minutes late, of 868 completed flights

Avg delay

96 min

Across delayed arrivals only, not all flights

Cancelled

1.25%

National rate is 1.81%

Whole route

74.1%

Every carrier on SFO to LAS, 6,066 flights

These figures cover 879 flights between July 2025 and June 2026. Beyond the headline rate, 15.9% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Frontier against every carrier on SFO to LAS

Frontier flew 879 of the 6,066 flights on SFO to LAS, about 14% of it. Its 65.6% on time is 9 points worse than the route as a whole, which runs 74.1%. Ranked by on-time rate it is number four of five carriers on the route, where the range runs from United at 79.6% to SkyWest at 50.0%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. United Airlines arrives on time 79.6% of the time; Southwest Airlines manages 66.3%. Sample sizes sit next to every figure, because a two-point gap across 1,312 flights means less than a ten-point one.

On-time performance by carrier on SFO to LAS
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines2,75779.6%55 min0.36%B+
Alaska Airlines1,11676.5%66 min0.81%B+
Southwest Airlines1,31266.3%64 min0.53%C+
Frontier Airlines (this page)87965.6%96 min1.25%C
SkyWest Airlinesthin sample250.0%81 min0.00%F+

The spread between United and Southwest is 13 points, wide enough that it should decide the booking. On a hundred trips that is 13 more arrivals inside the on-time window.

Flight by flight

Frontier flight numbers on SFO to LAS

Departure window

When Frontier runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 47 points, against 13 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am154 flights90.1%
  • 8am–11am105 flights74.3%
  • 11am–2pm128 flights43.3%
  • 2pm–5pm163 flights69.6%
  • 5pm–8pm107 flights72.0%
  • 8pm–5am222 flights51.2%

Scale runs 35% to 95%. 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 43.3% on time against 90.1% 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 222 flights scheduled in it.

Across the year

Frontier on SFO to LAS through the year

On-time rate by calendar month81J66F78M48A52M46J65J71A73S68O67N80D
Darker means more delays. Figures are on-time percentages.January best, June worst

June is the worst month at 46.3% on time, 35 points below January, the best at 80.8%. 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. May was the busiest month here, with 87 flights.

Across the week, Wednesday is the strongest day at 80.5% on time and Thursday the weakest at 59.2%. 21 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week66.2Mon60.0Tue80.5Wed59.2Thu62.7Fri76.9Sat59.7Sun
Monday: 66.2 percent on time. Tuesday: 60.0 percent on time. Wednesday: 80.5 percent on time. Thursday: 59.2 percent on time. Friday: 62.7 percent on time. Saturday: 76.9 percent on time. Sunday: 59.7 percent on time

Delay causes

Why Frontier runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 61% of the 29,000 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
    61%
  • Carrier
    27%
  • National Airspace System
    11%
  • Extreme weather
    1%

61% 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 29,000 reported delay minutes here, that single category outweighs weather by 61 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 28,547 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 90.1% on time here.

Cancellations sit at 1.25% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 15.9% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum 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 runs 64.3% on time across 875 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 879 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.

What to do with this

Booking Frontier on SFO to LAS

Put together: treat all of this as provisional. 879 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 65.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 868 completed flights over 12 months sit behind that.

Related

Where to go next

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.