Carrier route record
OOSFO→SLC
SkyWest Airlines · San Francisco to Salt Lake City
- Flights
- 1,103
- Period
- July 2025 to June 2026
- Share of route
- 32%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with SkyWest Airlines.
SkyWest on SFO to SLC 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 about an hour on average. That is a workable record, not a spotless one. That rests on 1,103 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 1,708 at 78.1% on time.
The US average over the same twelve months is 77.6%, so there is little to separate SkyWest on SFO to SLC from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.2%
Arrivals under 15 minutes late, of 1,090 completed flights
Avg delay
63 min
Across delayed arrivals only, not all flights
Cancelled
1.18%
National rate is 1.81%
Whole route
77.2%
Every carrier on SFO to SLC, 3,471 flights
These figures cover 1,103 flights between July 2025 and June 2026. The median arrival is 6 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 SLC
SkyWest flew 1,103 of the 3,471 flights on SFO to SLC, about 32% of it. Its 77.2% on time is about level with the route as a whole at 77.2%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from Delta at 78.1% to Frontier at 69.9%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The two carriers here are closely matched: about a point separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 1,708 | 78.1% | 77 min | 0.88% | B+ |
| SkyWest Airlines (this page) | 1,103 | 77.2% | 63 min | 1.18% | B |
| United Airlines | 482 | 76.7% | 55 min | 0.21% | B+ |
| Frontier Airlinesthin sample | 178 | 69.9% | 82 min | 1.12% | C |
No carrier stands out. Delta tops the table at 78.1%, about a point clear of the bottom, which is inside the range this kind of sample moves year to year.
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 26 points, against about a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am6 flights—
- 8am–11am215 flights91.6%
- 11am–2pm227 flights72.1%
- 2pm–5pm278 flights69.6%
- 5pm–8pm261 flights82.0%
- 8pm–5am116 flights65.8%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 91.6% of the time, against 65.8% for the overnight window. That is 26 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 278 flights scheduled in it.
Across the year
SkyWest on SFO to SLC through the year
June is the worst month at 65.0% on time, 31 points below September, the best at 95.5%. 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. April was the busiest month here, with 138 flights.
Across the week, Saturday is the strongest day at 83.3% on time and Monday the weakest at 70.4%. 13 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 16,000 reported delay minutes.
- 35%National Airspace System
- 30%Late-arriving aircraft
- 30%Carrier
- 4%Extreme weather
- 0%Security
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 5,439 minutes out of 16,000, against a national NAS share of 21%. The split is drawn from 15,562 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 91.6% on time here.
Cancellations sit at 1.18% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
7.1% 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 about an hour, which a normal layover absorbs.
The 599 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 68.8% on time across 1,104 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 1,103 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 SkyWest on SFO to SLC
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 95.5% on time and June 65.0%, a swing of 31 points. If the dates move at all, move them out of June before you think about anything else. 1,090 completed flights over 12 months sit behind that.
Related
Where to go next
- SFO to SLC, every carrier
- SkyWest on SLC to SFO, the return leg
- Delta Air Lines on SFO to SLC78.1%
- United Airlines on SFO to SLC76.7%
- Frontier Airlines on SFO to SLC69.9%
- SkyWest Airlines network-wide record
- San Francisco International (SFO) delay statistics
- Salt Lake City International (SLC) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.