Route reliability record
SLC→ATL
Salt Lake City to Atlanta
- Flights
- 2,972
- Period
- July 2025 to June 2026
- Distance
- 1,590 mi
- Carriers
- 2
This route earns a 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 10 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 2,972 flights, with a median arrival 10 minutes early.
Set against the rest of the country, this route's record is 10 points better than the US average of 77.6%. That gap is worth roughly 97 fewer late arrivals for every thousand flights.
Key figures
On time
87.3%
Arrivals under 15 minutes late, of 2,948 completed flights
Avg delay
65 min
Across delayed arrivals only, not all flights
Cancelled
0.54%
National rate is 1.81%
Best carrier
Delta
87.4% on time across 2,966 flights
These figures cover 2,972 flights between July 2025 and June 2026. The median arrival is 10 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
Which airline is most reliable on SLC to ATL
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 2,966 | 87.4% | 63 min | 0.54% | A+ |
| Frontier Airlinesthin sample | 6 | 50.0% | 347 min | 0.00% | F+ |
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 12 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–8am370 flights94.3%
- 8am–11am733 flights91.1%
- 11am–2pm657 flights85.5%
- 2pm–5pm471 flights83.6%
- 5pm–8pm365 flights82.6%
- 8pm–5am376 flights85.2%
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 94.3% of the time, against 82.6% for the evening window. That is 12 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 733 flights scheduled in it.
Across the year
When delays peak on this route
Twelve months, one bar each, drawn from the same 2,972 flights. The strip shows how much of this route's record is set by the calendar rather than by the operation.
July is the worst month at 81.4% on time, 11 points below February, the best at 92.1%. 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. January was the busiest month here, with 259 flights.
Across the week, Wednesday is the strongest day at 90.4% on time and Thursday the weakest at 85.0%. 5 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 59% 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.
- 59%Carrier
- 22%Late-arriving aircraft
- 16%National Airspace System
- 3%Extreme weather
- 0%Security
The largest share of delay minutes, 59%, 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 14,000 of the 24,000 delay minutes reported here. The split is drawn from 24,474 reported delay minutes.
Cancellations are rare at 0.54%, 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 actually costs
Badly late arrivals are rare here: only 4.3% 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.
At 1,590 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 83.0% on time across 2,965 flights, 4 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 4 points of difference.
The sample behind these figures is 2,972 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: avoid the 5pm–8pm departure. It runs 82.6% on time against 94.3% for the 5am–8am slot, and that 12 points is the largest single thing you control here. Delta Air Lines is the strongest operator if the fares are close. 2,948 completed flights over 12 months sit behind that.
Common questions
SLC to ATL questions
How often is SLC to ATL delayed?
About one flight in eight arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 12.7% of the 2,972 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is SLC to ATL compared with the rest of the country?
87.3% of flights arrive on time here against a national 77.6%, a difference of 10 points in its favour. That is worth a A+ on this site's grading scale.
What time of day has the fewest delays on SLC to ATL?
The 5am–8am departure window is the strongest at 94.3% on time. The 5pm–8pm window is the weakest at 82.6%, 12 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 July delays on SLC to ATL?
July is the weakest month at 81.4% on time, compared with 92.1% in February. Across the year that is 11 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
- ATL to SLC — the return legseparate record
- Salt Lake City International (SLC) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Delta Air Lines on-time record87.4%
- Frontier Airlines on-time record50.0%
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. SLC to ATL and ATL 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.