Carrier route record

DLSEA→GEG

Delta Air Lines · Seattle to Spokane

Flights: 343
Period: July 2025 to June 2026
Share of route: 7%
Carriers: 3

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

Delta on SEA to GEG sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 5 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 343 flights. The strongest carrier on the route with a full sample, SkyWest Airlines, flew 3,058 at 87.7% on time.

The national on-time rate over the same period is 77.6%, so Delta on SEA to GEG runs 5 points behind the country as a whole. Across a thousand flights that is about 49 extra late arrivals.

On time

72.7%

Arrivals under 15 minutes late, of 337 completed flights

Avg delay

79 min

Across delayed arrivals only, not all flights

Cancelled

1.46%

National rate is 1.81%

Whole route

82.5%

Every carrier on SEA to GEG, 5,221 flights

These figures cover 343 flights between July 2025 and June 2026. Beyond the headline rate, 9.5% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Delta against every carrier on SEA to GEG

Delta flew 343 of the 5,221 flights on SEA to GEG, about 7% of it. Its 72.7% on time is 10 points worse than the route as a whole, which runs 82.5%. Ranked by on-time rate it is last of three carriers on the route, where the range runs from SkyWest at 87.7% to Delta at 72.7%.

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 87.7% of the time; Alaska Airlines manages 75.6%. 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 SEA to GEG
Airline	Flights	On time	Avg delay	Cancelled	Grade
SkyWest Airlines	3,058	87.7%	55 min	1.05%	A
Alaska Airlines	1,820	75.6%	43 min	0.82%	B+
Delta Air Lines (this page)thin sample	343	72.7%	79 min	1.46%	C

The spread between SkyWest and Alaska is 12 points, wide enough that it should decide the booking. On a hundred trips that is 12 more arrivals inside the on-time window.

Departure window

When Delta runs best on this route

Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 343 flights.

5am–8am—
8am–11am—
11am–2pm—
2pm–5pm—
5pm–8pm45 flights68.2%
8pm–5am298 flights73.4%

Scale runs 60% to 80%. Rows with fewer than 30 flights show a dash.

The overnight block holds up unusually well at 73.4% on time across 298 flights. Red-eyes fly into empty airspace and empty gates, and they are the first rotation of the aircraft's day rather than the last. The 8pm–5am window is the busiest, with 298 flights scheduled in it.

Across the year

Delta on SEA to GEG through the year

Jul–Sep 202592 flights70.0%
Oct–Dec 202585 flights71.1%
Jan–Mar 202675 flights79.7%
Apr–Jun 202691 flights71.1%

Scale runs 60% to 85%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 72.7% on time across 343 flights.

Quarter by quarter Delta on SEA to GEG held fairly steady: 70.0% in Jul–Sep 2025, 71.1% in Oct–Dec 2025, 79.7% in Jan–Mar 2026 and 71.1% in Apr–Jun 2026. A spread of 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Across the week, Tuesday is the strongest day at 84.3% on time and Thursday the weakest at 62.5%. 22 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Carrier accounts for 59% of the 7,218 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
59%
Late-arriving aircraft
30%
National Airspace System
6%
Extreme weather
5%

The largest share of delay minutes, 59%, 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 4,260 of the 7,218 delay minutes reported here. The split is drawn from 7,218 reported delay minutes.

Cancellations sit at 1.46% against a national 1.81%, which is ordinary. Diversions add another 0.29%.

Connections and stage length

What a delay here costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.5% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

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 8pm–5am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 93.8% on time across 343 flights, 21 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 21 points of difference.

One caution: this is a thin sample. 343 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 SEA to GEG

Put together: treat all of this as provisional. 343 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 72.7% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 337 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