Route reliability record
BOS→LAS
Boston to Las Vegas
- Flights
- 1,638
- Period
- July 2025 to June 2026
- Distance
- 2,381 mi
- Carriers
- 2
This route sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 1,638 BOS to LAS flights, of which Delta Air Lines flew 593 at 77.9% on time.
Best time to fly BOS to LAS: a 11am–2pm departure, ideally on a Saturday. Flights in that window arrived on time 83.9% of the time and Saturday flights 80.2%, against 75.6% for the route overall.
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
75.6%
Arrivals under 15 minutes late, of 1,611 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
1.22%
National rate is 1.81%
Best carrier
Delta
77.9% on time across 593 flights
These figures cover 1,638 flights between July 2025 and June 2026. Beyond the headline rate, 8.6% 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 BOS to LAS
The two carriers here are closely matched: 4 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 | 593 | 77.9% | 58 min | 1.35% | B |
| JetBlue Airways | 1,045 | 74.3% | 69 min | 1.15% | C |
No carrier stands out. Delta tops the table at 77.9%, 4 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
Flights on BOS to LAS
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.
Best ways to make this trip
The most reliable ways to fly Boston to Las Vegas
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. BOS → LASBoston to Las Vegas | Delta Air Lines | 76.8% | 77.9% | 1.35% | 5am–8am, Sat | DL 497 07:40 |
| 2. BOS → LASBoston to Las Vegas | JetBlue Airways | 73.4% | 74.3% | 1.15% | 8am–11am, Tue | — |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
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 21 points, against 4 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am433 flights82.4%
- 8am–11am476 flights80.6%
- 11am–2pm31 flights83.9%
- 2pm–5pm72 flights67.6%
- 5pm–8pm468 flights69.1%
- 8pm–5am158 flights63.2%
Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 63.2% on time, against 83.9% for the 11am–2pm 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 8am–11am window is the busiest, with 476 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 15 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.
January is the weak month at 69.5% on time, against 84.9% in August. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. March was the busiest month here, with 168 flights.
Across the week, Saturday is the strongest day at 80.2% on time and Sunday the weakest at 71.1%. 9 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 26,000 reported delay minutes.
- 40%Late-arriving aircraft
- 30%Carrier
- 27%National Airspace System
- 3%Extreme weather
40% 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 26,000 reported delay minutes here, that single category outweighs weather by 12 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 25,840 reported delay minutes.
Cancellations sit at 1.22% against a national 1.81%, which is ordinary. Diversions add another 0.43%.
Connections and stage length
What a delay here actually costs
8.6% 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 last about an hour, which a normal layover absorbs.
At 2,381 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 runs 76.4% on time across 1,639 flights, within about a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
The sample behind these figures is 1,638 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 LAS 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. August runs 84.9% on time and January 69.5%, a swing of 15 points. If the dates move at all, move them out of January before you think about anything else. 1,611 completed flights over 12 months sit behind that.
Common questions
BOS to LAS questions
How often is BOS to LAS delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 24.4% of the 1,638 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on BOS to LAS?
Delta Air Lines leads at 77.9% on time across 593 flights. JetBlue Airways is at the other end on 74.3%, a gap of 4 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 BOS to LAS?
The 11am–2pm departure window is the strongest at 83.9% on time. The 8pm–5am window is the weakest at 63.2%, 21 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 January delays on BOS to LAS?
January is the weakest month at 69.5% on time, compared with 84.9% in August. Across the year that is 15 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
- LAS to BOS — the return legseparate record
- Boston Logan International (BOS) delay statistics
- Harry Reid International (LAS) delay statistics
- Delta Air Lines on BOS to LAS77.9%
- JetBlue Airways on BOS to LAS74.3%
- BOS to DCA, a related route74.0%
- LAX to LAS, a related route76.5%
- BOS to ORD, a related route72.7%
- Delta Air Lines on-time record77.9%
- JetBlue Airways on-time record74.3%
- 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. BOS to LAS and LAS to BOS 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.