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DelayAtlas

Carrier performance at one airport

OOSFO

SkyWest Airlines at San Francisco International

Departures
32,426
Period
June 2025 to May 2026
Routes
25
Rank here
#5 of 9
BGRADE

SkyWest Airlines at San Francisco lands a B, level with the national rate of 77.4%. Roughly one flight in five 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 32,426 flights, of which United Airlines flew 59,976 at 81.7% on time.

Measured against the airport rather than the country, SkyWest Airlines runs half a point behind the 78.3% weighted average across all carriers at SFO. That is the comparison worth making: every operator here works the same runways, the same airspace and the same weather.

Key figures

On time

77.8%

31,911 completed departures

Avg delay

74 min

Across delayed flights only

Cancelled

1.19%

At SFO, this carrier only

Rank here

#5

Of 9 carriers clearing the floor at SFO

These figures cover 32,000 flights between June 2025 and May 2026. The median arrival is 5 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.

Against the competition

Every carrier at SFO, ranked

The choice of carrier is not cosmetic here. United Airlines arrives on time 81.7% of the time; Southwest Airlines manages 61.9%. Sample sizes sit next to every figure, because a two-point gap across 9,132 flights means less than a ten-point one.

On-time performance of all carriers departing SFO
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines59,97681.7%59 min0.56%B+
Delta Air Lines13,73880.0%70 min1.21%B
JetBlue Airways4,34080.0%75 min1.57%B
American Airlines11,73978.5%101 min1.88%B
SkyWest Airlines (this page)32,42677.8%74 min1.19%B
Alaska Airlines10,62276.1%55 min1.13%B
Hawaiian Airlines59375.6%65 min1.85%B
Frontier Airlines3,32365.5%83 min1.93%C
Southwest Airlines9,13261.9%58 min0.79%D+

The spread between United and Southwest is 20 points, wide enough that it should decide the booking. On a hundred trips that is 20 more arrivals inside the on-time window.

Route by route

Where SkyWest Airlines flies from SFO

SkyWest Airlines operates 25 routes out of SFO with enough volume to report. Route records inside one carrier at one airport still spread widely, because a short shuttle and a transcontinental have very different exposure to a late inbound.

SkyWest Airlines routes from SFO
RouteFlightsOn timeAvg delayCancelledGrade
SFO to SNA · Santa Ana3,51780.7%60 min1.36%B
SFO to LAX · Los Angeles2,61078.6%59 min1.07%B
SFO to PSP · Palm Springs2,12377.5%78 min1.22%B
SFO to SAN · San Diego1,56167.0%57 min1.86%C
SFO to BOI · Boise1,44077.2%69 min0.28%B+
SFO to SMF · Sacramento1,37479.6%80 min1.67%B
SFO to BUR · Burbank1,31178.9%70 min1.45%B
SFO to FAT · Fresno1,30578.7%100 min1.46%B
SFO to ACV · Arcata/Eureka1,28977.7%82 min1.78%B
SFO to SLC · Salt Lake City1,16377.9%62 min1.12%B
SFO to SEA · Seattle1,11075.2%50 min1.08%B
SFO to SBP · San Luis Obispo1,02376.3%113 min1.08%B
SFO to RNO · Reno1,01375.9%69 min1.68%B
SFO to TUS · Tucson92981.6%61 min0.32%B+
SFO to RDD · Redding89676.4%147 min1.90%B
SFO to GEG · Spokane79578.5%62 min0.38%B+
SFO to MRY · Monterey68478.6%110 min0.58%B+
SFO to RDM · Redmond67473.0%60 min1.19%C
SFO to MFR · Medford61979.8%78 min1.78%B
SFO to PSC · Pasco60980.2%68 min0.16%B+
SFO to BFL · Bakersfield58072.5%65 min0.69%C+
SFO to SBA · Santa Barbara54979.1%97 min2.73%B
SFO to ABQ · Albuquerque52683.6%61 min0.57%B+
SFO to PHX · Phoenix51687.3%65 min0.78%A+
SFO to PDX · Portland48478.7%57 min0.21%B+

Departure window

Best time of day for this operation

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 18 points, against 20 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am1,582 flights92.2%
  • 8am–11am7,955 flights80.5%
  • 11am–2pm5,885 flights74.6%
  • 2pm–5pm6,540 flights75.3%
  • 5pm–8pm4,956 flights80.0%
  • 8pm–5am5,508 flights74.1%

Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 92.2% of the time, against 74.1% for the overnight window. That is 18 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on.

Across the year

Seasonal pattern

On-time rate by calendar month81J77F86M71A66M81J77J83A84S78O78N72D
Darker means more delays. Figures are on-time percentages.March best, May worst

Delays peak in May, when the on-time rate falls to 65.9%. March is the strongest month at 85.7%. Moving a flexible trip across that boundary buys 20 points.

Delay causes

What holds this operation up

  • National Airspace System
    30%
  • Carrier
    30%
  • Late-arriving aircraft
    30%
  • Extreme weather
    9%
  • Security
    0%

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 1.19% against a national 1.80%, which is ordinary. Diversions add another 0.39%.

7.9% 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 a little over an hour kind, which a normal layover absorbs.

32,426 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.

Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 85.7% on time and May 65.9%, a swing of 20 points. If the dates move at all, move them out of May before you think about anything else.

Common questions

SkyWest Airlines at SFO

How often is SkyWest Airlines at SFO delayed?

Roughly one flight in five arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 22.2% of the 32,426 flights in this analysis, against 22.6% nationally. Delayed flights are late by a little over an hour on average.

Which airline is most reliable on SkyWest Airlines at SFO?

United Airlines leads at 81.7% on time across 59,976 flights. Southwest Airlines is at the other end on 61.9%, a gap of 20 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 SkyWest Airlines at SFO?

The 5am–8am departure window is the strongest at 92.2% on time. The 8pm–5am window is the weakest at 74.1%, 18 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 SkyWest Airlines at SFO?

May is the weakest month at 65.9% on time, compared with 85.7% in March. Across the year that is 20 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

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