Carrier route record

OOSFO→STL

SkyWest Airlines · San Francisco to St. Louis

Flights: 235
Period: July 2025 to June 2026
Share of route: 30%
Carriers: 3

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

SkyWest on SFO to STL lands a B, level with the national rate of 77.6%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 235 flights, with a median arrival 7 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate SkyWest on SFO to STL from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

77.6%

Arrivals under 15 minutes late, of 228 completed flights

Avg delay

85 min

Across delayed arrivals only, not all flights

Cancelled

2.55%

National rate is 1.81%

Whole route

65.8%

Every carrier on SFO to STL, 781 flights

These figures cover 235 flights between July 2025 and June 2026. The median arrival is 7 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

SkyWest against every carrier on SFO to STL

SkyWest flew 235 of the 781 flights on SFO to STL, about 30% of it. Its 77.6% on time is 12 points better than the route as a whole, which runs 65.8%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from United at 80.7% to Southwest at 49.0%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on SFO to STL
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlinesthin sample	204	80.7%	52 min	0.49%	B+
SkyWest Airlines (this page)thin sample	235	77.6%	85 min	2.55%	B
Southwest Airlinesthin sample	342	49.0%	59 min	0.00%	F+

Departure window

When SkyWest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 15 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am—
8am–11am85 flights84.5%
11am–2pm57 flights69.6%
2pm–5pm41 flights76.3%
5pm–8pm—
8pm–5am52 flights76.0%

Scale runs 60% to 90%. 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 69.6% on time against 84.5% for 8am–11am. 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 85 flights scheduled in it.

Across the year

SkyWest on SFO to STL through the year

Jul–Sep 20256 flights—
Oct–Dec 202540 flights72.5%
Jan–Mar 2026104 flights87.9%
Apr–Jun 202685 flights68.7%

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 77.6% on time across 235 flights.

SkyWest on SFO to STL did not run the same all year. Its best quarter was Jan–Mar 2026 at 87.9% on time and its weakest Apr–Jun 2026 at 68.7%, a swing of 19 points on roughly 78 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Across the week, Friday is the strongest day at 84.8% on time and Wednesday the weakest at 73.3%. 12 points is a smaller lever than departure hour, but it is free.

Delay causes

Why SkyWest runs late on this route

Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 4,324 reported delay minutes.

Carrier
37%
National Airspace System
35%
Late-arriving aircraft
27%
Extreme weather
1%

The largest share of delay minutes, 37%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 1,592 of the 4,324 delay minutes reported here. The split is drawn from 4,324 reported delay minutes.

35% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 1,532 minutes out of 4,324, against a national NAS share of 21%.

Cancellations run at 2.55%, against 1.81% nationally. That is about one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here costs

7.5% 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 last an hour and a half, which a normal layover absorbs.

At 1,735 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

The return leg is a different operation and performs like one: it runs 63.2% on time across 233 flights, 14 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 14 points of difference.

One caution: this is a thin sample. 235 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 SkyWest on SFO to STL

Put together: treat all of this as provisional. 235 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 77.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 228 completed flights over 12 months sit behind that.

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.

Key figures