Carrier route record

DLSMF→SLC

Delta Air Lines · Sacramento to Salt Lake City

Flights: 1,509
Period: July 2025 to June 2026
Share of route: 70%
Carriers: 3

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

Delta on SMF 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 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 1,509 flights, with a median arrival 13 minutes early.

Set against the rest of the country, Delta's SMF to SLC record is 12 points better than the US average of 77.6%. That gap is worth roughly 121 fewer late arrivals for every thousand flights.

On time

89.7%

Arrivals under 15 minutes late, of 1,495 completed flights

Avg delay

80 min

Across delayed arrivals only, not all flights

Cancelled

0.86%

National rate is 1.81%

Whole route

87.6%

Every carrier on SMF to SLC, 2,158 flights

These figures cover 1,509 flights between July 2025 and June 2026. The median arrival is 13 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 SMF to SLC

Delta flew 1,509 of the 2,158 flights on SMF to SLC, most of the route. Its 89.7% on time is 2 points better than the route as a whole, which runs 87.6%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from SkyWest at 91.8% to Southwest at 81.6%. 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 SMF to SLC
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlinesthin sample	73	91.8%	64 min	0.00%	A+
Delta Air Lines (this page)	1,509	89.7%	80 min	0.86%	A+
Southwest Airlines	576	81.6%	60 min	0.17%	B+

Flight by flight

Delta flight numbers on SMF to SLC

Departure window

When Delta runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 13 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am365 flights96.4%
8am–11am332 flights92.4%
11am–2pm358 flights87.6%
2pm–5pm—
5pm–8pm454 flights83.9%
8pm–5am—

Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 96.4% of the time, against 83.9% for the evening window. That is 13 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 454 flights scheduled in it.

Across the year

Delta on SMF to SLC through the year

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

May is the best month on the calendar at 91.4% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. July was the busiest month here, with 147 flights.

Across the week, Monday is the strongest day at 92.7% on time and Tuesday the weakest at 87.5%. 5 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. Late-arriving aircraft accounts for 61% of the 12,000 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.

Late-arriving aircraft
61%
Carrier
35%
National Airspace System
4%
Extreme weather
1%

61% 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 12,000 reported delay minutes here, that single category outweighs weather by 61 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 12,358 reported delay minutes.

The largest share of delay minutes, 35%, 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 4,319 of the 12,000 delay minutes reported here.

Cancellations are rare at 0.86%, 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 4.5% 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 532 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 runs 87.3% on time across 1,509 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,509 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 Delta on SMF to SLC

Put together: avoid the 5pm–8pm departure. It runs 83.9% on time against 96.4% for the 5am–8am slot, and that 13 points is the largest single thing you control here. Southwest Airlines is the strongest operator if the fares are close. 1,495 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