Route profile
SLC→SFO
Flight reliability, delays and best times to fly from Salt Lake City to San Francisco, 599 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 28% of comparable major US routes (4,598 compared)
Calculated from 10,852 flights. How this is calculated
SLC → SFO arrives on time 71.5% of the time; the return trip, SFO → SLC, arrives on time 79.0% of the time, a 7.5-point gap between the two directions of the same city pair.
SLC → SFO spends 29.9 minutes on the ground on a 599-mile trip: 22.1 minutes from pushback to wheels-up at SLC and 7.8 minutes from touchdown to gate at SFO.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
Reliability on this route has fallen unusually sharply over the past year, a bigger swing than 96% of 5,368 comparable routes.
65.8% on time over the most recent 12 months (2025-08 to 2026-07), against 78.2% in the 12 months before (2024-08 to 2025-07), a change of 12.4 points.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 5,368 in the comparison.
Why SLC → SFO flights are cancelled
July 2023 – July 2026
SLC → SFO cancelled 77 of 10,852 scheduled flights — about 1 in every 141. The reason filed most often was the airline, 59.7% of the cancellations coded on this route — about 1 in every 236 scheduled flights.
Share of cancellations
Of 77 cancelled departures carrying a reason code.
What each reason means
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
46 cancellations, 59.7% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
17 cancellations, 22.1% of the total.
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
14 cancellations, 18.2% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
77 coded cancellations were recorded on SLC → SFO; the section appears from 50.
When it goes wrong
July 2023 – July 2026
57 min late
against a median of 3 min early
SLC → SFO has an average that understates its risk: a typical arrival is 3 min early, but the worst tenth are 60 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.
Percentiles over 10,852 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SFO after arriving from SLC.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 45% | Likely to miss |
| 45 min | 28% | High risk |
| 60 min | 19% | High risk |
| 90 min | 9.4% | Some risk |
| 120 min | 5.4% | Some risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.71% of the time and diverts 0.14% of the time, which a late arrival never shows up in.
Chance of missing is the share of 10,760 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 57 minutes late (90th-percentile gate arrival delay), over 10,852 operations.
Any other layover length: connection checker.
Best time to fly
SLC → SFO flights departing 12–3 PM arrived on time 83.1% of the time, against 63.1% for 6–9 PM departures, a gap of 20.0 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 90.9% on time from 627 flights
- 7 AM: 71.1% on time from 628 flights
- 8 AM: 70.2% on time from 1,297 flights
- 9 AM: 63.3% on time from 563 flights
- 10 AM: 66.8% on time from 375 flights
- 11 AM: 67.4% on time from 1,166 flights
- 12 PM: 81.4% on time from 380 flights
- 1 PM: 86.8% on time from 259 flights
- 2 PM: 80.7% on time from 146 flights
- 3 PM: 70.9% on time from 1,214 flights
- 4 PM: 73.4% on time from 1,089 flights
- 5 PM: 65.7% on time from 620 flights
- 6 PM: 82.8% on time from 186 flights
- 7 PM: too few flights to score
- 8 PM: 59.5% on time from 1,149 flights
- 9 PM: 77.7% on time from 212 flights
- 10 PM: 74.4% on time from 733 flights
- 11 PM: 80.5% on time from 174 flights
Why SLC → SFO runs late
July 2023 – July 2026
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for SLC → SFO. Only delays of 15 minutes or more are attributed.
How this route holds up in bad weather
July 2023 – July 2026
The harder-hit end is SFO, where the flight lands. Its figure counts departures from SFO, so it says more about how that airport copes than about this route. Bad weather cancels 1.7 times the normal rate at SFO against barely any change at SLC. Cancelled in bad weather against normal hours: SLC 0.6% against 0.6%, SFO 1.5% against 0.9%. Flights that did leave SLC in bad weather arrived on time 71.0% of the time, against 84.8% in normal hours.
Bad weather and normal hours at the airports
Scheduled departures, July 2023 – July 2026| Departures from | SLC | SFO |
|---|---|---|
| Cancelled in bad weather | 0.6% | 1.5% |
| Cancelled in normal hours | 0.6% | 0.9% |
| Arrived on time, bad weather | 71.0% | 73.0% |
| Arrived on time, normal hours | 84.8% | 79.8% |
| Departures in bad weather | 20,014 | 36,006 |
Of the carriers on this route, SkyWest Airlines (0.4% cancelled against 0.7% for the other carriers at SLC) cancelled the fewest departures from SLC in bad weather and Frontier Airlines (1.9% cancelled against 0.6% for the other carriers at SLC) the most.
This route’s airlines in bad weather at SLC
All departures from SLC| Airline | Bad-weather departures | Cancelled | Other carriers |
|---|---|---|---|
| SkyWest Airlines | 5,888 | 0.4%below the others | 0.7% |
| Delta Air Lines | 9,247 | 0.5%about level | 0.7% |
| United Airlines | 840 | 0.8%about level | 0.6% |
| Frontier Airlines | 525 | 1.9%above the others | 0.6% |
These are airport figures, not route figures: every scheduled departure from SLC and SFO, to any destination, in hours the weather report called bad. The airline rows count each carrier’s departures from SLC on every route.
Weather source and limits. In full: SLC (airlines), SFO, What Weather Costs Each Airport, Who Cancels More When the Weather Turns, Airports That Change Places When Weather Turns.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Delta Air Lines | 5,196 | 70.0% | 0.60% | 0 min | 8.9% |
| SkyWest Airlines | 3,758 | 73.6% | 0.72% | -5 min | 9.4% |
| United Airlines | 1,369 | 73.9% | 0.73% | -10 min | 10.9% |
| Frontier Airlines | 529 | 63.8% | 1.70% | 3 min | 14.6% |
Delta Air Lines flew 47.9% of the 10,852 flights listed. Frontier Airlines cancelled 1.70% of its flights here against 0.60% for Delta Air Lines.
United Airlines arrived on time 10.1 percentage points more often than Frontier Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
DL1091 (10:59 PM) arrived on time 74.2% of the time, 5.3 points more often than DL902 (11:25 AM) at 68.9%.
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Monday the least, a gap of 10.3 percentage points.
By month
- Jan: 79.1%
- Feb: 67.1%
- Mar: 69.7%
- Apr: 62.1%
- May: 62.2%
- Jun: 61.8%
- Jul: 68.5%
- Aug: 77.4%
- Sep: 79.8%
- Oct: 80.2%
- Nov: 76.2%
- Dec: 75.4%
June is historically the weakest month and October the strongest, a spread of 18.4 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 78.1% from 292 flights
- August 2023: 76.8% from 284 flights
- September 2023: 78.0% from 287 flights
- October 2023: 84.7% from 333 flights
- November 2023: 84.0% from 313 flights
- December 2023: 78.5% from 320 flights
- January 2024: 70.9% from 290 flights
- February 2024: 52.5% from 265 flights
- March 2024: 49.8% from 274 flights
- April 2024: 53.0% from 287 flights
- May 2024: 53.0% from 289 flights
- June 2024: 64.4% from 264 flights
- July 2024: 79.6% from 289 flights
- August 2024: 73.9% from 289 flights
- September 2024: 81.1% from 275 flights
- October 2024: 84.7% from 288 flights
- November 2024: 70.8% from 276 flights
- December 2024: 74.5% from 307 flights
- January 2025: 87.5% from 297 flights
- February 2025: 72.1% from 284 flights
- March 2025: 72.3% from 320 flights
- April 2025: 80.8% from 328 flights
- May 2025: 85.5% from 327 flights
- June 2025: 78.0% from 306 flights
- July 2025: 76.6% from 314 flights
- August 2025: 81.6% from 295 flights
- September 2025: 80.4% from 250 flights
- October 2025: 70.3% from 283 flights
- November 2025: 72.5% from 265 flights
- December 2025: 72.8% from 295 flights
- January 2026: 78.4% from 269 flights
- February 2026: 75.4% from 284 flights
- March 2026: 83.9% from 325 flights
- April 2026: 49.8% from 294 flights
- May 2026: 46.1% from 307 flights
- June 2026: 42.4% from 291 flights
- July 2026: 39.7% from 296 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 65.8% against 78.2% in the 12 months before — declining by 12.4 percentage points.
Data and methodology
Calculated by FlyerIntel from 10,852 SLC → SFO flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed