Route reliability record
DFW→SLC
Dallas-Fort Worth to Salt Lake City
- Flights
- 3,871
- Period
- July 2025 to June 2026
- Distance
- 989 mi
- Carriers
- 4
This route sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 8 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 3,871 flights, of which Delta Air Lines flew 1,459 at 81.5% on time.
The national on-time rate over the same period is 77.6%, so this route runs 8 points behind the country as a whole. Across a thousand flights that is about 80 extra late arrivals.
Key figures
On time
69.6%
Arrivals under 15 minutes late, of 3,766 completed flights
Avg delay
74 min
Across delayed arrivals only, not all flights
Cancelled
2.51%
National rate is 1.81%
Best carrier
Delta
81.5% on time across 1,459 flights
These figures cover 3,871 flights between July 2025 and June 2026. Beyond the headline rate, 11.6% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on DFW to SLC
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 81.5% of the time; American Airlines manages 60.6%. Sample sizes sit next to every figure, because a two-point gap across 2,214 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Frontier Airlinesthin sample | 189 | 82.8% | 64 min | 1.59% | B |
| Delta Air Lines | 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+ |
American Airlines cancels 3.3% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 36 points, against 21 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am92 flights86.4%
- 8am–11am764 flights81.7%
- 11am–2pm1,003 flights70.5%
- 2pm–5pm556 flights76.8%
- 5pm–8pm928 flights63.2%
- 8pm–5am528 flights50.9%
Scale runs 40% to 90%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 50.9% on time, against 86.4% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 11am–2pm window is the busiest, with 1,003 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 24 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
August is the worst month at 54.2% on time, 24 points below February, the best at 77.7%. 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. March was the busiest month here, with 358 flights.
Across the week, Tuesday is the strongest day at 75.7% on time and Saturday the weakest at 66.9%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 50% of the 84,000 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.
- 50%Late-arriving aircraft
- 36%Carrier
- 8%National Airspace System
- 5%Extreme weather
- 0%Security
50% 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 84,000 reported delay minutes here, that single category outweighs weather by 9 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 84,042 reported delay minutes.
The largest share of delay minutes, 36%, 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 31,000 of the 84,000 delay minutes reported here.
Cancellations run at 2.51%, against 1.81% nationally. That is about one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.6% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
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 is a different operation and performs like one: it runs 78.6% on time across 3,869 flights, 9 points above 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 9 points of difference.
The sample behind these figures is 3,871 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 this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. February runs 77.7% on time and August 54.2%, a swing of 24 points. If the dates move at all, move them out of August before you think about anything else. 3,766 completed flights over 12 months sit behind that.
Common questions
DFW to SLC questions
How often is DFW to SLC delayed?
Roughly one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 30.4% of the 3,871 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on DFW to SLC?
Delta Air Lines leads at 81.5% on time across 1,459 flights. American Airlines is at the other end on 60.6%, a gap of 21 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on DFW to SLC?
The 5am–8am departure window is the strongest at 86.4% on time. The 8pm–5am window is the weakest at 50.9%, 36 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are August delays on DFW to SLC?
August is the weakest month at 54.2% on time, compared with 77.7% in February. Across the year that is 24 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- SLC to DFW — the return legseparate record
- Dallas/Fort Worth International (DFW) delay statistics
- Salt Lake City International (SLC) delay statistics
- Frontier Airlines on-time record82.8%
- Delta Air Lines on-time record81.5%
- American Airlines on-time record60.6%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. DFW to SLC and SLC to DFW are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.