Route reliability record
LAS→BOS
Las Vegas to Boston
- Flights
- 1,639
- Period
- July 2025 to June 2026
- Distance
- 2,381 mi
- Carriers
- 2
This route lands a B, about a point worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 1,639 LAS to BOS flights, of which Delta Air Lines flew 593 at 76.5% on time.
Best time to fly LAS to BOS: a 2pm–5pm departure, ideally on a Tuesday. Flights in that window arrived on time 79.9% of the time and Tuesday flights 85.3%, against 76.4% 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
76.4%
Arrivals under 15 minutes late, of 1,611 completed flights
Avg delay
78 min
Across delayed arrivals only, not all flights
Cancelled
1.34%
National rate is 1.81%
Best carrier
Delta
76.5% on time across 593 flights
These figures cover 1,639 flights between July 2025 and June 2026. Beyond the headline rate, 10.4% 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 LAS to BOS
The two carriers here are closely matched: half a point 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 | 76.5% | 71 min | 1.52% | B |
| JetBlue Airways | 1,046 | 76.3% | 81 min | 1.24% | B |
No carrier stands out. Delta tops the table at 76.5%, half a point clear of the bottom, which is inside the range this kind of sample moves year to year.
Best ways to make this trip
The most reliable ways to fly Las Vegas to Boston
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. LAS → BOSLas Vegas to Boston | JetBlue Airways | 75.4% | 76.3% | 1.24% | 2pm–5pm, Tue | — |
| 2. LAS → BOSLas Vegas to Boston | Delta Air Lines | 75.3% | 76.5% | 1.52% | 8pm–5am, Sat | — |
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 is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 1,639 flights.
- 5am–8am30 flights—
- 8am–11am259 flights71.9%
- 11am–2pm563 flights74.2%
- 2pm–5pm212 flights79.9%
- 5pm–8pm—
- 8pm–5am575 flights78.5%
Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.
The best window here is not the first bank but the 2pm–5pm slot at 79.9% on time, ahead of 8am–11am at 71.9%. Where the curve peaks mid-day rather than at dawn, the constraint is usually congestion at one end rather than the aircraft's own rotation. The 8pm–5am window is the busiest, with 575 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 24 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.
Delays peak in October, when the on-time rate falls to 63.4%. June is the strongest month at 87.1%. Moving a flexible trip across that boundary buys 24 points. March was the busiest month here, with 168 flights.
Across the week, Tuesday is the strongest day at 85.3% on time and Sunday the weakest at 67.5%. 18 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 30,000 reported delay minutes.
- 38%National Airspace System
- 33%Late-arriving aircraft
- 26%Carrier
- 3%Extreme weather
- 0%Security
38% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 11,000 minutes out of 30,000, against a national NAS share of 21%. The split is drawn from 29,507 reported delay minutes.
Cancellations sit at 1.34% against a national 1.81%, which is ordinary. Diversions add another 0.37%.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.4% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
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 75.6% on time across 1,638 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 1,639 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 BOS 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. June runs 87.1% on time and October 63.4%, a swing of 24 points. If the dates move at all, move them out of October before you think about anything else. 1,611 completed flights over 12 months sit behind that.
Common questions
LAS to BOS questions
How often is LAS to BOS 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 23.6% of the 1,639 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.
Which airline is most reliable on LAS to BOS?
Delta Air Lines leads at 76.5% on time across 593 flights. JetBlue Airways is at the other end on 76.3%, a gap of half a point. 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 BOS?
The 2pm–5pm departure window is the strongest at 79.9% on time. The 8am–11am window is the weakest at 71.9%, 8 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 October delays on LAS to BOS?
October is the weakest month at 63.4% on time, compared with 87.1% in June. Across the year that is 24 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
- BOS to LAS — the return legseparate record
- Harry Reid International (LAS) delay statistics
- Boston Logan International (BOS) delay statistics
- Delta Air Lines on LAS to BOS76.5%
- JetBlue Airways on LAS to BOS76.3%
- LAS to LAX, a related route78.8%
- DCA to BOS, a related route71.4%
- LAS to DEN, a related route77.0%
- Delta Air Lines on-time record76.5%
- JetBlue Airways on-time record76.3%
- Why the first flight of the morning is statistically safest
- How often a connection fails at the major US hubs
Direction matters. LAS to BOS and BOS to LAS 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.