Carrier route record

OOPHX→BOI

SkyWest Airlines · Phoenix to Boise

Flights: 1,001
Period: July 2025 to June 2026
Share of route: 50%
Carriers: 5

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with SkyWest Airlines.

SkyWest on PHX to BOI 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 6 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 1,001 flights, with a median arrival 8 minutes early.

Set against the rest of the country, SkyWest's PHX to BOI record is 6 points better than the US average of 77.6%. That gap is worth roughly 64 fewer late arrivals for every thousand flights.

On time

84.0%

Arrivals under 15 minutes late, of 993 completed flights

Avg delay

69 min

Across delayed arrivals only, not all flights

Cancelled

0.60%

National rate is 1.81%

Whole route

80.4%

Every carrier on PHX to BOI, 1,986 flights

These figures cover 1,001 flights between July 2025 and June 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

SkyWest against every carrier on PHX to BOI

SkyWest flew 1,001 of the 1,986 flights on PHX to BOI, most of the route. Its 84.0% on time is 4 points better than the route as a whole, which runs 80.4%. Ranked by on-time rate it is number two of five carriers on the route, where the range runs from Alaska at 100.0% to American at 67.3%. Three of those carriers flew fewer than 365 flights here, so treat their positions as rough.

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.

On-time performance by carrier on PHX to BOI
Airline	Flights	On time	Avg delay	Cancelled	Grade
Alaska Airlinesthin sample	5	100.0%	—	0.00%	A+
SkyWest Airlines (this page)	1,001	84.0%	69 min	0.60%	B+
Southwest Airlines	813	77.3%	45 min	0.25%	B+
Envoy Airthin sample	115	77.2%	34 min	0.00%	B+
American Airlinesthin sample	52	67.3%	60 min	0.00%	C+

Departure window

When SkyWest runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 10 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–8am1 flights—
8am–11am259 flights84.8%
11am–2pm162 flights88.7%
2pm–5pm251 flights84.9%
5pm–8pm64 flights87.3%
8pm–5am264 flights78.6%

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

The best window here is not the first bank but the 11am–2pm slot at 88.7% on time, ahead of 8pm–5am at 78.6%. 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 264 flights scheduled in it.

Across the year

SkyWest on PHX to BOI through the year

Darker means more delays. Figures are on-time percentages.December best, October worst

Delays peak in October, when the on-time rate falls to 78.9%. December is the strongest month at 90.4%. Moving a flexible trip across that boundary buys 12 points. October was the busiest month here, with 114 flights.

Across the week, Monday is the strongest day at 87.8% on time and Thursday the weakest at 80.1%. 8 points is a smaller lever than departure hour, but it is free.

Delay causes

Why SkyWest runs late on this route

One category carries most of the weight here. Carrier accounts for 55% of the 11,000 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.

Carrier
55%
Late-arriving aircraft
24%
Extreme weather
15%
National Airspace System
6%
Security
0%

Extreme weather accounts for 15% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.4 times the usual weather exposure. The split is drawn from 10,933 reported delay minutes.

The largest share of delay minutes, 55%, 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 6,028 of the 11,000 delay minutes reported here.

Cancellations are rare at 0.60%, 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 costs

Badly late arrivals are rare here: only 4.3% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

The 735 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 runs 86.5% on time across 1,000 flights, within 3 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

One caution: this is a thin sample. 1,001 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 SkyWest on PHX to BOI

Put together: treat all of this as provisional. 1,001 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 84.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 993 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures