Carrier route record

DLDFW→SLC

Delta Air Lines · Dallas-Fort Worth to Salt Lake City

Flights: 1,459
Period: July 2025 to June 2026
Share of route: 38%
Carriers: 4

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

Delta on DFW to SLC lands a B, 4 points better than the national rate of 77.6%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 1,459 flights, with a median arrival 7 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Delta on DFW to SLC from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

81.5%

Arrivals under 15 minutes late, of 1,436 completed flights

Avg delay

92 min

Across delayed arrivals only, not all flights

Cancelled

1.51%

National rate is 1.81%

Whole route

69.6%

Every carrier on DFW to SLC, 3,871 flights

These figures cover 1,459 flights between July 2025 and June 2026. The median arrival is 7 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 DFW to SLC

Delta flew 1,459 of the 3,871 flights on DFW to SLC, about 38% of it. Its 81.5% on time is 12 points better than the route as a whole, which runs 69.6%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from Frontier at 82.8% to Envoy at 55.6%. Two 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 DFW to SLC
Airline	Flights	On time	Avg delay	Cancelled	Grade
Frontier Airlinesthin sample	189	82.8%	64 min	1.59%	B
Delta Air Lines (this page)	1,459	81.5%	92 min	1.51%	B
American Airlines	2,214	60.6%	68 min	3.25%	D−
Envoy Airthin sample	9	55.6%	37 min	0.00%	D+

Flight by flight

Delta flight numbers on DFW to SLC

DL 129108:1088.0% · 365 flights

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 16 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–8am55 flights81.8%
8am–11am310 flights89.1%
11am–2pm363 flights82.9%
2pm–5pm365 flights82.3%
5pm–8pm365 flights72.9%
8pm–5am1 flights—

Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 89.1% of the time, against 72.9% for the evening window. That is 16 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 365 flights scheduled in it.

Across the year

Delta on DFW to SLC through the year

Darker means more delays. Figures are on-time percentages.January best, August worst

August is the worst month at 70.7% on time, 21 points below January, the best at 92.0%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. December was the busiest month here, with 125 flights.

Across the week, Wednesday is the strongest day at 83.1% on time and Sunday the weakest at 78.3%. 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. Carrier accounts for 46% of the 24,000 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.

Carrier
46%
Late-arriving aircraft
45%
National Airspace System
6%
Extreme weather
3%

45% 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 24,000 reported delay minutes here, that single category outweighs weather by 15 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 24,364 reported delay minutes.

The largest share of delay minutes, 46%, 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 11,000 of the 24,000 delay minutes reported here.

Cancellations sit at 1.51% against a national 1.81%, which is ordinary. Diversions add another 0.07%.

Connections and stage length

What a delay here costs

7.2% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last an hour and a half, which a normal layover absorbs.

The 989 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 80.4% on time across 1,458 flights, within about a point 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 1,459 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 DFW to SLC

Put together: the calendar is the biggest lever here, not the carrier or the hour. January runs 92.0% on time and August 70.7%, a swing of 21 points. If the dates move at all, move them out of August before you think about anything else. 1,436 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