Route reliability record
LAS→BOI
Las Vegas to Boise
- Flights
- 1,400
- Period
- July 2025 to June 2026
- Distance
- 519 mi
- Carriers
- 5
This route sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 4 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 1,400 LAS to BOI flights, with a median arrival 3 minutes early.
Best time to fly LAS to BOI: a 8am–11am departure, ideally on a Saturday. Flights in that window arrived on time 87.6% of the time and Saturday flights 83.5%, against 73.3% for the route overall.
The national on-time rate over the same period is 77.6%, so this route runs 4 points behind the country as a whole. Across a thousand flights that is about 43 extra late arrivals.
Key figures
On time
73.3%
Arrivals under 15 minutes late, of 1,398 completed flights
Avg delay
56 min
Across delayed arrivals only, not all flights
Cancelled
0.14%
National rate is 1.81%
Best carrier
Southwest
72.5% on time across 1,049 flights
These figures cover 1,400 flights between July 2025 and June 2026. The median arrival is 3 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 BOI
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 |
|---|---|---|---|---|---|
| Alaska Airlinesthin sample | 71 | 85.9% | 104 min | 0.00% | A+ |
| SkyWest Airlinesthin sample | 219 | 74.8% | 78 min | 0.46% | C+ |
| Southwest Airlines | 1,049 | 72.5% | 49 min | 0.10% | C+ |
| Allegiant Airthin sample | 14 | 71.4% | 78 min | 0.00% | C+ |
| Spirit Airlinesthin sample | 47 | 66.0% | 80 min | 0.00% | C+ |
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 23 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am27 flights—
- 8am–11am372 flights87.6%
- 11am–2pm43 flights81.4%
- 2pm–5pm345 flights68.6%
- 5pm–8pm181 flights64.6%
- 8pm–5am432 flights66.8%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 64.6% on time, against 87.6% for the 8am–11am 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 8pm–5am window is the busiest, with 432 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 29 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 54.7% on time, 29 points below August, the best at 83.3%. 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. July was the busiest month here, with 127 flights.
Across the week, Saturday is the strongest day at 83.5% on time and Sunday the weakest at 65.1%. 18 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. Late-arriving aircraft accounts for 56% of the 20,000 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.
- 56%Late-arriving aircraft
- 32%Carrier
- 10%National Airspace System
- 2%Extreme weather
- 0%Security
56% 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 20,000 reported delay minutes here, that single category outweighs weather by 35 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 20,140 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 87.6% on time here.
Cancellations are rare at 0.14%, below the national 1.81% 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
7.7% 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.
The 519 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 81.1% on time across 1,401 flights, 8 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 8 points of difference.
The sample behind these figures is 1,400 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 BOI 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 83.3% on time and June 54.7%, a swing of 29 points. If the dates move at all, move them out of June before you think about anything else. 1,398 completed flights over 12 months sit behind that.
Common questions
LAS to BOI questions
How often is LAS to BOI 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 26.7% of the 1,400 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is LAS to BOI compared with the rest of the country?
73.3% of flights arrive on time here against a national 77.6%, a difference of 4 points against it. That is worth a C+ on this site's grading scale.
What time of day has the fewest delays on LAS to BOI?
The 8am–11am departure window is the strongest at 87.6% on time. The 5pm–8pm window is the weakest at 64.6%, 23 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 BOI?
June is the weakest month at 54.7% on time, compared with 83.3% in August. Across the year that is 29 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
- BOI to LAS — the return legseparate record
- Harry Reid International (LAS) delay statistics
- SkyWest Airlines on LAS to BOI74.8%
- Southwest Airlines on LAS to BOI72.5%
- LAS to LAX, a related route78.8%
- SEA to BOI, a related route85.8%
- LAS to DEN, a related route77.0%
- Alaska Airlines on-time record85.9%
- SkyWest Airlines on-time record74.8%
- Southwest Airlines on-time record72.5%
- 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. LAS to BOI and BOI 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.