Carrier route record

OOPHX→SEA

SkyWest Airlines · Phoenix to Seattle

Flights: 506
Period: July 2025 to June 2026
Share of route: 7%
Carriers: 7

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

SkyWest on PHX to SEA lands a B+, 5 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 506 flights. The strongest carrier on the route with a full sample, Delta Air Lines, flew 1,764 at 87.8% on time.

Delta Air Lines is the most reliable of the four carriers covered here at 87.8% on time across 1,764 flights.

On time

82.6%

Arrivals under 15 minutes late, of 501 completed flights

Avg delay

61 min

Across delayed arrivals only, not all flights

Cancelled

0.59%

National rate is 1.81%

Whole route

82.7%

Every carrier on PHX to SEA, 7,269 flights

These figures cover 506 flights between July 2025 and June 2026. The median arrival is 7 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 SEA

SkyWest flew 506 of the 7,269 flights on PHX to SEA, about 7% of it. Its 82.6% on time is about level with the route as a whole at 82.7%. Ranked by on-time rate it is number five of seven carriers on the route, where the range runs from Delta at 87.8% to Southwest at 64.8%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 87.8% of the time; Southwest Airlines manages 64.8%. Sample sizes sit next to every figure, because a two-point gap across 1,037 flights means less than a ten-point one.

On-time performance by carrier on PHX to SEA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	1,764	87.8%	73 min	0.85%	A+
Envoy Air	692	87.1%	45 min	0.00%	A+
Frontier Airlinesthin sample	165	86.1%	80 min	0.00%	A+
Alaska Airlines	2,903	84.9%	56 min	0.76%	B+
SkyWest Airlines (this page)	506	82.6%	61 min	0.59%	B+
American Airlinesthin sample	202	81.6%	53 min	0.50%	B+
Southwest Airlines	1,037	64.8%	43 min	0.58%	D+

The spread between Delta and Southwest is 23 points, wide enough that it should decide the booking. On a hundred trips that is 23 more arrivals inside the on-time window.

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 14 points, against 23 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am66 flights92.3%
8am–11am126 flights83.2%
11am–2pm45 flights86.0%
2pm–5pm103 flights82.4%
5pm–8pm163 flights77.9%
8pm–5am3 flights—

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 92.3% of the time, against 77.9% for the evening window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 163 flights scheduled in it.

Across the year

SkyWest on PHX to SEA through the year

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

December is the weak month at 67.2% on time, against 93.3% in March. 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. January was the busiest month here, with 75 flights.

Across the week, Tuesday is the strongest day at 89.2% on time and Friday the weakest at 77.8%. 11 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 70% of the 5,297 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
70%
Extreme weather
13%
National Airspace System
9%
Late-arriving aircraft
8%
Security
0%

Extreme weather accounts for 13% 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 2.1 times the usual weather exposure. The split is drawn from 5,297 reported delay minutes.

The largest share of delay minutes, 70%, 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 3,683 of the 5,297 delay minutes reported here.

Cancellations are rare at 0.59%, 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

5.2% 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 1,107 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 80.2% on time across 506 flights, within 2 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. 506 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 SEA

Put together: treat all of this as provisional. 506 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 82.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 501 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