Route reliability record

GEG→SEA

Spokane to Seattle

Flights: 5,183
Period: July 2025 to June 2026
Distance: 224 mi
Carriers: 3

This route earns a A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs about 55 minutes. That rests on 5,183 flights, of which SkyWest Airlines flew 3,020 at 88.2% on time.

Set against the rest of the country, this route's record is 8 points better than the US average of 77.6%. That gap is worth roughly 83 fewer late arrivals for every thousand flights.

On time

85.9%

Arrivals under 15 minutes late, of 5,125 completed flights

Avg delay

55 min

Across delayed arrivals only, not all flights

Cancelled

1.06%

National rate is 1.81%

Best carrier

SkyWest

88.2% on time across 3,020 flights

These figures cover 5,183 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

Which airline is most reliable on GEG to SEA

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 88.2% of the time; Alaska Airlines manages 80.6%. Sample sizes sit next to every figure, because a two-point gap across 1,820 flights means less than a ten-point one.

On-time performance by carrier on GEG to SEA
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Linesthin sample	343	93.8%	145 min	1.46%	A
SkyWest Airlines	3,020	88.2%	60 min	0.99%	A+
Alaska Airlines	1,820	80.6%	43 min	1.10%	B

SkyWest leads Alaska by 8 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

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 13 points, against 8 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,692 flights92.4%
8am–11am610 flights79.4%
11am–2pm1,230 flights83.5%
2pm–5pm667 flights87.1%
5pm–8pm962 flights80.7%
8pm–5am22 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 92.4% of the time, against 79.4% for the morning window. That is 13 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 1,692 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 12 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.

Darker means more delays. Figures are on-time percentages.May best, July worst

July is the worst month at 79.4% on time, 12 points below May, the best at 91.5%. 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 544 flights.

Across the week, Wednesday is the strongest day at 89.1% on time and Thursday the weakest at 79.5%. 10 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 39,000 reported delay minutes.

Carrier
39%
Late-arriving aircraft
26%
Extreme weather
19%
National Airspace System
16%
Security
0%

Extreme weather accounts for 19% 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 3.1 times the usual weather exposure. The split is drawn from 39,345 reported delay minutes.

The largest share of delay minutes, 39%, 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 15,000 of the 39,000 delay minutes reported here.

Cancellations sit at 1.06% against a national 1.81%, which is ordinary. Diversions add another 0.06%.

Connections and stage length

What a delay here actually costs

Badly late arrivals are rare here: only 3.3% 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.

At 224 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 82.5% on time across 5,221 flights, 3 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 3 points of difference.

The sample behind these figures is 5,183 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.

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. May runs 91.5% on time and July 79.4%, a swing of 12 points. If the dates move at all, move them out of July before you think about anything else. 5,125 completed flights over 12 months sit behind that.

Common questions

GEG to SEA questions

How often is GEG to SEA delayed?

About one flight in seven arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 14.1% of the 5,183 flights in this analysis, against 22.4% nationally. Delayed flights are late by about 55 minutes on average.

Which airline is most reliable on GEG to SEA?

SkyWest Airlines leads at 88.2% on time across 3,020 flights. Alaska Airlines is at the other end on 80.6%, a gap of 8 points. 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 GEG to SEA?

The 5am–8am departure window is the strongest at 92.4% on time. The 8am–11am window is the weakest at 79.4%, 13 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 July delays on GEG to SEA?

July is the weakest month at 79.4% on time, compared with 91.5% in May. Across the year that is 12 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. GEG to SEA and SEA to GEG are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures