Route reliability record
SLC→DFW
Salt Lake City to Dallas-Fort Worth
- Flights
- 3,869
- Period
- July 2025 to June 2026
- Distance
- 989 mi
- Carriers
- 4
This route lands a B, about a point better than the national rate of 77.6%. About one flight in five arrive 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 3,869 flights, of which Delta Air Lines flew 1,458 at 80.4% on time.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.6%
Arrivals under 15 minutes late, of 3,733 completed flights
Avg delay
90 min
Across delayed arrivals only, not all flights
Cancelled
2.58%
National rate is 1.81%
Best carrier
Delta
80.4% on time across 1,458 flights
These figures cover 3,869 flights between July 2025 and June 2026. Beyond the headline rate, 8.3% 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 SLC to DFW
The two carriers here are closely matched: 3 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 1,458 | 80.4% | 70 min | 1.30% | B |
| Envoy Airthin sample | 9 | 77.8% | 46 min | 0.00% | B+ |
| American Airlines | 2,213 | 77.5% | 103 min | 3.43% | B− |
| Frontier Airlinesthin sample | 189 | 77.2% | 80 min | 2.65% | B |
American Airlines cancels 3.4% 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 26 points, against 3 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am981 flights88.2%
- 8am–11am758 flights86.1%
- 11am–2pm860 flights77.9%
- 2pm–5pm764 flights62.7%
- 5pm–8pm456 flights73.4%
- 8pm–5am50 flights73.9%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 88.2% of the time, against 62.7% for the afternoon window. That is 26 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 981 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 20 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 66.7% on time, 20 points below February, the best at 86.2%. 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, Wednesday is the strongest day at 83.6% on time and Sunday the weakest at 73.0%. 11 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. Carrier accounts for 44% of the 72,000 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.
- 44%Carrier
- 41%Late-arriving aircraft
- 14%National Airspace System
- 1%Extreme weather
- 0%Security
41% 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 72,000 reported delay minutes here, that single category outweighs weather by 28 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 71,977 reported delay minutes.
The largest share of delay minutes, 44%, 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 32,000 of the 72,000 delay minutes reported here.
Cancellations run at 2.58%, 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
8.3% 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 are the an hour and a half kind, 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 is a different operation and performs like one: it runs 69.6% on time across 3,871 flights, 9 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 9 points of difference.
The sample behind these figures is 3,869 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 86.2% on time and August 66.7%, a swing of 20 points. If the dates move at all, move them out of August before you think about anything else. 3,733 completed flights over 12 months sit behind that.
Common questions
SLC to DFW questions
How often is SLC to DFW delayed?
About one flight in five arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 21.4% of the 3,869 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
Which airline is most reliable on SLC to DFW?
Delta Air Lines leads at 80.4% on time across 1,458 flights. American Airlines is at the other end on 77.5%, a gap of 3 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 SLC to DFW?
The 5am–8am departure window is the strongest at 88.2% on time. The 2pm–5pm window is the weakest at 62.7%, 26 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 SLC to DFW?
August is the weakest month at 66.7% on time, compared with 86.2% in February. Across the year that is 20 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
- DFW to SLC — the return legseparate record
- Salt Lake City International (SLC) delay statistics
- Dallas/Fort Worth International (DFW) delay statistics
- Delta Air Lines on-time record80.4%
- Envoy Air on-time record77.8%
- American Airlines on-time record77.5%
- 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. SLC to DFW and DFW to SLC 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.