Carrier route record
DLBOS→LAS
Delta Air Lines · Boston to Las Vegas
- Flights
- 551
- Period
- September 2025 to August 2026
- Share of route
- 35%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on BOS to LAS lands a B, level with the national rate of 77.3%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 551 flights, with a median arrival 6 minutes early.
The US average over the same twelve months is 77.3%, so there is little to separate Delta on BOS to LAS from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
77.5%
Arrivals under 15 minutes late, of 543 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
1.27%
National rate is 1.89%
Whole route
74.7%
Every carrier on BOS to LAS, 1,596 flights
These figures cover 551 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
Delta against every carrier on BOS to LAS
Delta flew 551 of the 1,596 flights on BOS to LAS, about 35% of it. Its 77.5% on time is 3 points better than the route as a whole, which runs 74.7%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Delta at 77.5% to JetBlue at 73.2%.
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 (this page) | 551 | 77.5% | 59 min | 1.27% | B |
| JetBlue Airways | 1,045 | 73.2% | 74 min | 1.53% | C |
Flight by flight
Delta flight numbers on BOS to LAS
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Departure window
When Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 15 points, against half a point between the best and worst carrier.
- 5am–8am199 flights86.4%
- 8am–11am166 flights75.5%
- 11am–2pm4 flights—
- 2pm–5pm—
- 5pm–8pm166 flights71.8%
- 8pm–5am16 flights—
Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 86.4% of the time, against 71.8% for the evening window. That is 15 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 199 flights scheduled in it.
Across the year
Delta on BOS to LAS through the year
February is the weak month at 68.1% on time, against 87.1% in July. 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 61 flights.
Across the week, Saturday is the strongest day at 83.1% on time and Monday the weakest at 70.1%, a spread of 13 points.
Arrival by arrival
How late Delta on BOS to LAS runs when it is late
Delta on BOS to LAS often beats the schedule: 181 of 543 completed flights, 33%, arrived 15 minutes or more early. The 122 late arrivals split 51 under half an hour, 36 between 30 and 60 minutes, and 35 an hour or more.
- 15+ min early181 flights33.3%
- Within 15 min240 flights44.2%
- 15–29 min late51 flights9.4%
- 30–59 min late36 flights6.6%
- 1–2 hours late22 flights4.1%
- 2+ hours late13 flights2.4%
Scale runs 0% to 100%.
Share of 543 completed flights by arrival against schedule.
A late pushback is often recovered here: of 116 departures that left 15 minutes late or more, 38 still arrived on time. In the other direction, 44 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at LAS.
The worst days
Worst days for Delta on BOS to LAS
The latest arrival of the period was on 19 February 2026, 8 hours 9 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 19 February 2026 | 8 hours 9 minutes | Carrier |
| 5 January 2026 | 6 hours 18 minutes | Carrier |
| 8 March 2026 | 5 hours 55 minutes | Carrier |
| 27 January 2026 | 5 hours 17 minutes | Late-arriving aircraft |
| 3 August 2026 | 4 hours 22 minutes | National Airspace System |
Delay causes
Why Delta runs late on this route
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 7,228 reported delay minutes.
- 41%Carrier
- 30%Late-arriving aircraft
- 27%National Airspace System
- 2%Extreme weather
The largest share of delay minutes, 41%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,942 of the 7,228 delay minutes reported here. The split is drawn from 7,228 reported delay minutes.
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 86.4% on time here.
Cancellations sit at 1.27% against a national 1.89%, which is ordinary. Diversions add another 0.18%.
Connections and stage length
What a delay here costs
6.4% 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 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 is a different operation and performs like one: it runs 73.7% on time across 551 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.
One caution: this is a thin sample. 551 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking Delta on BOS to LAS
Put together: treat all of this as provisional. 551 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 77.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 543 completed flights over 12 months sit behind that.
Related
Where to go next
- BOS to LAS, every carrier
- Delta on LAS to BOS, the return leg
- JetBlue Airways on BOS to LAS73.2%
- Delta Air Lines network-wide record
- Boston Logan International (BOS) delay statistics
- Harry Reid International (LAS) delay statistics
- 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
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.