Carrier route record
DLSJC→SLC
Delta Air Lines · San Jose to Salt Lake City
- Flights
- 924
- Period
- September 2025 to August 2026
- Share of route
- 52%
- Carriers
- 3
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on SJC to SLC earns an A+. Nearly every flight arrives inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 16 points better than the national rate of 77.3%. When something does go wrong the average delay runs an hour and a half. That rests on 924 flights, with a median arrival 17 minutes early.
Set against the rest of the country, Delta's SJC to SLC record is 16 points better than the US average of 77.3%. That gap is worth roughly 159 fewer late arrivals for every thousand flights.
Key figures
On time
93.2%
Arrivals under 15 minutes late, of 917 completed flights
Avg delay
86 min
Across delayed arrivals only, not all flights
Cancelled
0.54%
National rate is 1.89%
Whole route
91.9%
Every carrier on SJC to SLC, 1,794 flights
These figures cover 924 flights between September 2025 and August 2026. The median arrival is 17 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.
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Carrier by carrier
Delta against every carrier on SJC to SLC
Delta flew 924 of the 1,794 flights on SJC to SLC, most of the route. Its 93.2% on time is about level with the route as a whole at 91.9%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 94.1% to Southwest at 78.7%. One 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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| SkyWest Airlines | 662 | 94.1% | 86 min | 0.15% | A+ |
| Delta Air Lines (this page) | 924 | 93.2% | 86 min | 0.54% | A+ |
| Southwest Airlinesthin sample | 208 | 78.7% | 56 min | 0.48% | B+ |
Flight by flight
Delta flight numbers on SJC to SLC
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 Delta runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 924 flights.
- 5am–8am365 flights94.7%
- 8am–11am34 flights94.1%
- 11am–2pm365 flights91.8%
- 2pm–5pm5 flights—
- 5pm–8pm155 flights92.9%
- 8pm–5am—
Scale runs 85% to 100%. Rows with fewer than 30 flights show a dash.
The time of day barely matters here. The 5am–8am window tops the set at 94.7% and 11am–2pm sits at 91.8%, 3 points apart across 924 flights. Pick the departure that suits the trip: whatever is going wrong here is not accumulating over the course of the day. The 5am–8am window is the busiest, with 365 flights scheduled in it.
Across the year
Delta on SJC to SLC through the year
Delays peak in September, when the on-time rate falls to 86.7%. December is the strongest month at 96.7%. Moving a flexible trip across that boundary buys 10 points. January was the busiest month here, with 97 flights.
Across the week, Wednesday is the strongest day at 94.7% on time and Sunday the weakest at 90.7%, a spread of 4 points.
Arrival by arrival
How late Delta on SJC to SLC runs when it is late
Delta on SJC to SLC often beats the schedule: 532 of 917 completed flights, 58%, arrived 15 minutes or more early. The 62 late arrivals split 18 under half an hour, 16 between 30 and 60 minutes, and 28 an hour or more.
- 15+ min early532 flights58.0%
- Within 15 min323 flights35.2%
- 15–29 min late18 flights2.0%
- 30–59 min late16 flights1.7%
- 1–2 hours late16 flights1.7%
- 2+ hours late12 flights1.3%
Scale runs 0% to 100%.
Share of 917 completed flights by arrival against schedule.
24 of 81 late departures made up the time and arrived on time, 30% of them. Only 5 left on time and still arrived late.
The worst days
Worst days for Delta on SJC to SLC
The latest arrival of the period was on 17 November 2025, 7 hours 32 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On four of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 17 November 2025 | 7 hours 32 minutes | Late-arriving aircraft |
| 12 May 2026 | 7 hours 14 minutes | Carrier |
| 13 May 2026 | 6 hours 9 minutes | Carrier |
| 26 July 2026 | 5 hours 26 minutes | Carrier |
| 6 March 2026 | 3 hours 34 minutes | Carrier |
Delay causes
Why Delta runs late on this route
Late-arriving aircraft accounts for 53% of the 5,333 delay minutes carriers reported here, and the remaining four split what is left.
- 53%Late-arriving aircraft
- 45%Carrier
- 2%National Airspace System
- 0%Extreme weather
53% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 5,333 reported delay minutes here, that single category outweighs weather by 53 to one. The split is drawn from 5,333 reported delay minutes.
The largest share of delay minutes, 45%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,374 of the 5,333 delay minutes reported here.
Cancellations are rare at 0.54%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here costs
Badly late arrivals are rare here: only 3.1% land an hour or more behind schedule, against 8.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 584 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 is a different operation and performs like one: it runs 85.7% on time across 924 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.
One caution: this is a thin sample. 924 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 Delta on SJC to SLC
Put together: treat all of this as provisional. 924 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 93.2% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 917 completed flights over 12 months sit behind that.
Related
Where to go next
- SJC to SLC, every carrier
- Delta on SLC to SJC, the return leg
- SkyWest Airlines on SJC to SLC94.1%
- Southwest Airlines on SJC to SLC78.7%
- Delta Air Lines network-wide record
- Norman Y. Mineta San Jose International (SJC) delay statistics
- Salt Lake City International (SLC) delay statistics
- Why the first flight of the morning is statistically safest
- Worst months to fly in the US, ranked by the data
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.