Carrier route record

DLSJC→SLC

Delta Air Lines · San Jose to Salt Lake City

Flights: 892
Period: July 2025 to June 2026
Share of route: 49%
Carriers: 3

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

Delta on SJC to SLC earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 15 points better than the national rate of 77.6%. When something does go wrong the average delay runs an hour and a half. That rests on 892 flights, with a median arrival 17 minutes early.

Set against the rest of the country, Delta's SJC to SLC record is 15 points better than the US average of 77.6%. That gap is worth roughly 147 fewer late arrivals for every thousand flights.

On time

92.3%

Arrivals under 15 minutes late, of 886 completed flights

Avg delay

100 min

Across delayed arrivals only, not all flights

Cancelled

0.67%

National rate is 1.81%

Whole route

92.2%

Every carrier on SJC to SLC, 1,808 flights

These figures cover 892 flights between July 2025 and June 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.

Carrier by carrier

Delta against every carrier on SJC to SLC

Delta flew 892 of the 1,808 flights on SJC to SLC, about 49% of it. Its 92.3% on time is about level with the route as a whole at 92.2%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 94.9% to Southwest at 83.4%. 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.

On-time performance by carrier on SJC to SLC
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	692	94.9%	85 min	0.14%	A+
Delta Air Lines (this page)	892	92.3%	100 min	0.67%	A+
Southwest Airlinesthin sample	224	83.4%	53 min	0.45%	B+

Flight by flight

Delta flight numbers on SJC to SLC

DL 131406:0095.3% · 365 flights

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 892 flights.

5am–8am365 flights95.3%
8am–11am34 flights94.1%
11am–2pm365 flights89.9%
2pm–5pm5 flights—
5pm–8pm123 flights90.2%
8pm–5am—

Scale runs 80% to 100%. 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 89.9% on time against 95.3% for 5am–8am. 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 5am–8am window is the busiest, with 365 flights scheduled in it.

Across the year

Delta on SJC to SLC through the year

Darker means more delays. Figures are on-time percentages.December best, September worst

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 94.5% on time and Thursday the weakest at 89.0%. 6 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Carrier accounts for 50% of the 6,784 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.

Carrier
50%
Late-arriving aircraft
49%
National Airspace System
1%

49% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 6,784 reported delay minutes here, that single category outweighs weather by 49 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 6,784 reported delay minutes.

The largest share of delay minutes, 50%, 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 3,412 of the 6,784 delay minutes reported here.

Cancellations are rare at 0.67%, below the national 1.81% 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 3.6% land an hour or more behind schedule, against 8.1% 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. 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 84.6% on time across 892 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. 892 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. 892 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 92.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 886 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