Route reliability record
ATL→SLC
Atlanta to Salt Lake City
- Flights
- 2,965
- Period
- September 2025 to August 2026
- Distance
- 1,590 mi
- Carriers
- 2
This route lands a B+, 5 points better than the national rate of 77.3%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 2,965 ATL to SLC flights, with a median arrival 6 minutes early.
Best time to fly ATL to SLC: a 8am–11am departure, ideally on a Wednesday. Flights in that window arrived on time 88.4% of the time and Wednesday flights 87.9%, against 82.7% for the route overall.
Set against the rest of the country, this route's record is 5 points better than the US average of 77.3%. That gap is worth roughly 54 fewer late arrivals for every thousand flights.
Key figures
On time
82.7%
Arrivals under 15 minutes late, of 2,946 completed flights
Avg delay
60 min
Across delayed arrivals only, not all flights
Cancelled
0.44%
National rate is 1.89%
Best carrier
Delta
82.7% on time across 2,959 flights
These figures cover 2,965 flights between September 2025 and August 2026. The median arrival is 6 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.
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Carrier by carrier
Which airline is most reliable on ATL to SLC
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 | 2,959 | 82.7% | 60 min | 0.44% | B+ |
| Frontier Airlinesthin sample | 6 | 66.7% | 70 min | 0.00% | C+ |
Flight by flight
Flights on ATL to SLC
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
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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.
- 5am–8am22 flights—
- 8am–11am739 flights88.4%
- 11am–2pm372 flights87.9%
- 2pm–5pm732 flights82.6%
- 5pm–8pm640 flights76.5%
- 8pm–5am460 flights77.1%
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 88.4% of the time, against 76.5% 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 739 flights scheduled in it.
Explore
Filter ATL to SLC by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On ATL to SLC, the best departure window is 8am–11am at 88.4% on time and the worst is 5pm–8pm at 76.5%, a wide gap of 11.9 points. All US flights leaving 8am–11am ran 83.9%.
- 5–8am—
- 8–11am88.4%
- 11am–2pm87.9%
- 2–5pm82.6%
- 5–8pm76.5%
- 8pm–5am77.1%
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 13 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 76.8% on time, 13 points below September, the best at 90.1%. 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 256 flights.
Across the week, Wednesday is the strongest day at 87.9% on time and Saturday the weakest at 80.7%, a spread of 7 points.
Delay causes
Why this route gets delayed
Carrier accounts for 58% of the 31,000 delay minutes carriers reported here, and the remaining four split what is left.
- 58%Carrier
- 23%Late-arriving aircraft
- 16%National Airspace System
- 3%Extreme weather
The largest share of delay minutes, 58%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 18,000 of the 31,000 delay minutes reported here. The split is drawn from 30,760 reported delay minutes.
Cancellations are rare at 0.44%, below the national 1.89% 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
5.5% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
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 86.4% on time across 2,974 flights, 4 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 4 points of difference.
The sample behind these figures is 2,965 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.
Work out the risk of missing a connection in SLC after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 90.1% on time and August 76.8%, a swing of 13 points. If the dates move at all, move them out of August before you think about anything else. 2,946 completed flights over 12 months sit behind that.
Common questions
ATL to SLC questions
How often is ATL to SLC delayed?
About one flight in six arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 17.3% of the 2,965 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
How reliable is ATL to SLC compared with the rest of the country?
82.7% of flights arrive on time here against a national 77.3%, a difference of 5 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on ATL to SLC?
The 8am–11am departure window is the strongest at 88.4% on time. The 5pm–8pm window is the weakest at 76.5%, 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 August delays on ATL to SLC?
August is the weakest month at 76.8% on time, compared with 90.1% in September. Across the year that is 13 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 ATL — the return legseparate record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Salt Lake City International (SLC) delay statistics
- ATL to LGA, a related route72.3%
- DEN to SLC, a related route78.2%
- ATL to MCO, a related route70.3%
- Delta Air Lines on-time record82.7%
- Frontier Airlines on-time record66.7%
- The best time of day to fly, according to 7.05 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. ATL to SLC and SLC to ATL are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.