Route reliability record
LAS→ATL
Las Vegas to Atlanta
- Flights
- 4,840
- Period
- June 2025 to May 2026
- Distance
- 1,747 mi
- Carriers
- 4
This route earns a B. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.4%. When something does go wrong the average delay runs a little over an hour. That rests on 4,840 flights, of which Delta Air Lines flew 3,356 at 86.4% on time.
Delta Air Lines is the most reliable of the three carriers covered here at 86.4% on time across 3,356 flights.
Key figures
On time
84.2%
Arrivals under 15 minutes late, of 4,770 completed flights
Avg delay
73 min
Across delayed arrivals only, not all flights
Cancelled
1.10%
National rate is 1.80%
Best carrier
Delta
86.4% on time across 3,356 flights
These figures cover 4,840 flights between June 2025 and May 2026. The median arrival is 8 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 LAS to ATL
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 86.4% of the time; Frontier Airlines manages 73.2%. Sample sizes sit next to every figure, because a two-point gap across 543 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Delta Air Lines | 3,356 | 86.4% | 83 min | 0.95% | A+ |
| Southwest Airlines | 721 | 83.6% | 39 min | 0.69% | B+ |
| Spirit Airlinesthin sample | 220 | 79.7% | 70 min | 0.91% | B+ |
| Frontier Airlines | 543 | 73.2% | 72 min | 2.58% | C |
The spread between Delta and Frontier is 13 points, wide enough that it should decide the booking. On a hundred trips that is 13 more arrivals inside the on-time window.
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 14 points, against 13 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am874 flights92.5%
- 8am–11am837 flights87.7%
- 11am–2pm962 flights79.7%
- 2pm–5pm504 flights83.6%
- 5pm–8pm42 flights78.6%
- 8pm–5am1,621 flights80.8%
Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 92.5% of the time, against 78.6% for the evening window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on.
Across the year
When delays peak on this route
This route's year swings by 16 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.
June is the worst month at 73.7% on time, 16 points below February, the best at 89.4%. 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.
Across the week, Wednesday is the strongest day at 90.8% on time and Monday the weakest at 81.2%. 10 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 51% of the 55,000 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.
- 51%Carrier
- 33%Late-arriving aircraft
- 16%National Airspace System
- 0%Extreme weather
- 0%Security
The largest share of delay minutes, 51%, 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 28,000 of the 55,000 delay minutes reported here.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 92.5% on time here.
Cancellations sit at 1.10% against a national 1.80%, which is ordinary. Diversions add another 0.35%.
Connections and stage length
What a delay here actually costs
5.1% of arrivals land an hour or more late, close to the national 8.2%. 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 a little over an hour kind, which a normal layover absorbs.
At 1,747 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 74.9% on time across 4,843 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 4,840 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 89.4% on time and June 73.7%, a swing of 16 points. If the dates move at all, move them out of June before you think about anything else.
Common questions
LAS to ATL questions
How often is LAS to ATL delayed?
About one flight in six arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 15.8% of the 4,840 flights in this analysis, against 22.6% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on LAS to ATL?
Delta Air Lines leads at 86.4% on time across 3,356 flights. Frontier Airlines is at the other end on 73.2%, a gap of 13 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 LAS to ATL?
The 5am–8am departure window is the strongest at 92.5% on time. The 5pm–8pm window is the weakest at 78.6%, 14 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 June delays on LAS to ATL?
June is the weakest month at 73.7% on time, compared with 89.4% in February. Across the year that is 16 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 LAS — the return legseparate record
- Harry Reid International (LAS) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Delta Air Lines on-time record86.4%
- Southwest Airlines on-time record83.6%
- Spirit Airlines on-time record79.7%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
Direction matters. LAS to ATL and ATL to LAS 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, June 2025 to May 2026. Updated monthly. How this data is collected.