Flight number record

AS 398

Alaska Airlines · Seattle to Houston

Route: SEA → IAH
Departs: 17:40
Flights: 359
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s AS 398, check with Alaska Airlines.

AS 398 lands a B+, 2 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That is a workable record, not a spotless one. That rests on 359 flights, with a median arrival 6 minutes early.

On time

79.6%

Arrivals under 15 minutes late, of 357 completed flights

Avg delay

51 min

Across delayed arrivals only, not all flights

Cancelled

0.56%

National rate is 1.81%

1 hour+ late

4.5%

National rate is 8.1%

These figures cover 359 flights between July 2025 and June 2026. The median arrival is 6 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.

Schedule

When AS 398 flies

AS 398 flies SEA to IAH without a single fixed slot. Its most common scheduled departure was 17:40, used on 94 of 359 flights, with 17:39 (69 flights) and 17:30 (54 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 17:4094 flights26.2%
Departs 17:3969 flights19.2%
Departs 17:3054 flights15.0%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.

A 17:40 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and AS 398 runs 11 points better at 79.6%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

AS 398 next to SEA to IAH

Every carrier on SEA to IAH combined arrived on time 80.3% of the time across 2,095 flights, so AS 398 is about level with it. Alaska flew 852 flights on the same city pair under all its flight numbers, including this one, and those ran 74.3% on time. Across its whole network Alaska Airlines managed 79.1%, close to this flight's figure.

AS 398 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AS 398thin sample	359	79.6%	51 min	0.56%	B+
All Alaska Airlines on SEA–IAH	852	74.3%	45 min	0.70%	C+
All carriers on SEA–IAH	2,095	80.3%	56 min	0.62%	B+
Alaska Airlines, whole network	293,372	79.1%	52 min	1.28%	B

Across the year

AS 398 quarter by quarter

AS 398 did not run the same all year. Its best quarter was Jan–Mar 2026 at 85.2% on time and its weakest Jul–Sep 2025 at 68.5%, a swing of 17 points on roughly 90 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Jul–Sep 202592 flights68.5%
Oct–Dec 202588 flights82.8%
Jan–Mar 202689 flights85.2%
Apr–Jun 202690 flights82.2%

Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, AS 398 did best on Saturday at 92.0% on time and worst on Sunday at 71.2%. Each day rests on about 51 flights, so a gap of 21 points is worth noticing but could still narrow in another year.

Delay causes

Why AS 398 runs late

One category carries most of the weight here. Carrier accounts for 50% of the 3,732 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
50%
Late-arriving aircraft
37%
National Airspace System
10%
Extreme weather
3%

37% 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 3,732 reported delay minutes here, that single category outweighs weather by 12 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 3,732 delay minutes reported on AS 398.

Cancellations are rare at 0.56%, 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 routes

What a delay on this flight costs

Badly late arrivals are rare here: only 4.5% 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 1,874 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

Every one of the 359 flights under AS 398 in the data flew SEA to IAH. The number was not reused on any other city pair, which makes this a clean record of one route.

One caution: this is a thin sample. 359 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 AS 398

For a booking, read AS 398 as 79.6% on time with 0.56% cancelled over 359 flights. Those are rates from the past twelve months, not a forecast for any particular day.

Where to go next

A flight number here means Alaska Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.

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