Carrier route record
F9SLC→SFO
Frontier Airlines · Salt Lake City to San Francisco
- Flights
- 206
- Period
- September 2025 to August 2026
- Share of route
- 6%
- Carriers
- 4
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Frontier Airlines.
Frontier on SLC to SFO 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 206 flights. The strongest carrier on the route with a full sample, United Airlines, flew 504 at 68.2% on time.
United Airlines is the most reliable of the three carriers covered here at 68.2% on time across 504 flights.
Key figures
On time
65.2%
Arrivals under 15 minutes late, of 201 completed flights
Avg delay
97 min
Across delayed arrivals only, not all flights
Cancelled
2.43%
National rate is 1.89%
Whole route
63.4%
Every carrier on SLC to SFO, 3,433 flights
These figures cover 206 flights between September 2025 and August 2026. Beyond the headline rate, 16.4% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Frontier against every carrier on SLC to SFO
Frontier flew 206 of the 3,433 flights on SLC to SFO, about 6% of it. Its 65.2% on time is 2 points better than the route as a whole, which runs 63.4%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from United at 68.2% to Delta at 61.6%.
The choice of carrier is not cosmetic here. United Airlines arrives on time 68.2% of the time; Delta Air Lines manages 61.6%. Sample sizes sit next to every figure, because a two-point gap across 1,712 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 504 | 68.2% | 70 min | 0.20% | C+ |
| Frontier Airlines (this page)thin sample | 206 | 65.2% | 97 min | 2.43% | C |
| SkyWest Airlines | 1,011 | 63.9% | 75 min | 1.19% | D |
| Delta Air Lines | 1,712 | 61.6% | 52 min | 0.93% | D+ |
United leads Delta by 7 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 23 points, against 7 points between the best and worst carrier.
- 5am–8am—
- 8am–11am4 flights—
- 11am–2pm15 flights—
- 2pm–5pm63 flights66.1%
- 5pm–8pm79 flights71.1%
- 8pm–5am45 flights47.7%
Scale runs 40% to 75%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 47.7% on time, against 71.1% for the 5pm–8pm slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5pm–8pm window is the busiest, with 79 flights scheduled in it.
Across the year
Frontier on SLC to SFO through the year
- Jul–Sep 202517 flights—
- Oct–Dec 202537 flights72.2%
- Jan–Mar 202633 flights75.8%
- Apr–Jun 202663 flights59.0%
- Jul–Sep 202656 flights66.7%
Scale runs 50% to 80%. 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 65.2% on time across 206 flights.
Frontier on SLC to SFO did not run the same all year. Its best quarter was Jan–Mar 2026 at 75.8% on time and its weakest Apr–Jun 2026 at 59.0%, a swing of 17 points on roughly 52 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 67.4% on time and Sunday the weakest at 57.5%, a spread of 10 points.
Arrival by arrival
How late Frontier on SLC to SFO runs when it is late
Frontier on SLC to SFO often beats the schedule: 74 of 201 completed flights, 37%, arrived 15 minutes or more early. The 70 late arrivals split 16 under half an hour, 21 between 30 and 60 minutes, and 33 an hour or more.
- 15+ min early74 flights36.8%
- Within 15 min57 flights28.4%
- 15–29 min late16 flights8.0%
- 30–59 min late21 flights10.4%
- 1–2 hours late16 flights8.0%
- 2+ hours late17 flights8.5%
Scale runs 0% to 100%.
Share of 201 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 69 departures that left 15 minutes late or more, only 5 made it up before arrival. 6 flights left on time and still arrived late.
The worst days
Worst days for Frontier on SLC to SFO
The latest arrival of the period was on 13 April 2026, 14 hours 41 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 13 April 2026 | 14 hours 41 minutes | Carrier |
| 17 May 2026 | 9 hours 20 minutes | Late-arriving aircraft |
| 15 July 2026 | 6 hours 39 minutes | Late-arriving aircraft |
| 3 August 2026 | 4 hours 41 minutes | Carrier |
| 4 September 2025 | 4 hours 9 minutes | Late-arriving aircraft |
Delay causes
Why Frontier runs late on this route
Late-arriving aircraft accounts for 50% of the 6,810 delay minutes carriers reported here, and the remaining four split what is left.
- 50%Late-arriving aircraft
- 26%National Airspace System
- 23%Carrier
- 1%Extreme weather
50% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 6,810 reported delay minutes here, that single category outweighs weather by 50 to one. The split is drawn from 6,810 reported delay minutes.
Cancellations sit at 2.43% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
16.4% 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.
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.
The return leg runs 65.8% on time across 206 flights, within half 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. 206 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 SLC to SFO
Put together: treat all of this as provisional. 206 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 65.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 201 completed flights over 12 months sit behind that.
Related
Where to go next
- SLC to SFO, every carrier
- Frontier on SFO to SLC, the return leg
- United Airlines on SLC to SFO68.2%
- SkyWest Airlines on SLC to SFO63.9%
- Delta Air Lines on SLC to SFO61.6%
- Frontier Airlines network-wide record
- Salt Lake City International (SLC) delay statistics
- San Francisco International (SFO) delay statistics
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
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.