Flight number record

AS 398

Alaska Airlines · Seattle to Houston

Route: SEA → IAH
Departs: 17:39
Flights: 344
Period: September 2025 to August 2026

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

AS 398 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 7 points better than the national rate of 77.3%. When something does go wrong the average delay runs about 55 minutes. That rests on 344 flights, with a median arrival 9 minutes early.

Set against the rest of the country, AS 398's record is 7 points better than the US average of 77.3%. That gap is worth roughly 72 fewer late arrivals for every thousand flights.

On time

84.5%

Arrivals under 15 minutes late, of 341 completed flights

Avg delay

55 min

Across delayed arrivals only, not all flights

Cancelled

0.87%

National rate is 1.89%

1 hour+ late

3.2%

National rate is 8.3%

These figures cover 344 flights between September 2025 and August 2026. The median arrival is 9 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.

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Schedule

When AS 398 flies

AS 398 flies SEA to IAH without a single fixed slot. Its most common scheduled departure was 17:39, used on 69 of 344 flights, with 23:57 (68 flights) and 17:30 (54 flights) next.

Departs 17:3969 flights20.1%
Departs 23:5768 flights19.8%
Departs 17:3054 flights15.7%

Scale runs 0% to 100%.

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

A 17:39 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and AS 398 runs 17 points better at 84.5%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

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Against the route

AS 398 next to SEA to IAH

Every carrier on SEA to IAH combined arrived on time 84.0% of the time across 2,071 flights, so AS 398 is about level with it. Alaska flew 841 flights on the same city pair under all its flight numbers, including this one, and those ran 78.2% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight beats by 5 points.

AS 398 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AS 398thin sample	344	84.5%	55 min	0.87%	B+
All Alaska Airlines on SEA–IAH	841	78.2%	47 min	0.48%	B+
All carriers on SEA–IAH	2,071	84.0%	61 min	0.29%	B+
Alaska Airlines, whole network	309,844	79.7%	52 min	1.20%	B

Across the year

AS 398 quarter by quarter

Quarter by quarter AS 398 held fairly steady: 90.0% in Jul–Sep 2025, 82.8% in Oct–Dec 2025, 85.2% in Jan–Mar 2026, 82.2% in Apr–Jun 2026 and 87.0% in Jul–Sep 2026. A spread of 8 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202530 flights90.0%
Oct–Dec 202588 flights82.8%
Jan–Mar 202689 flights85.2%
Apr–Jun 202690 flights82.2%
Jul–Sep 202647 flights87.0%

Scale runs 75% to 95%.

By weekday, AS 398 did best on Saturday at 93.6% on time and worst on Sunday at 77.6%. Each day rests on about 49 flights, so a gap of 16 points is worth noticing but could still narrow in another year.

Arrival by arrival

How late AS 398 runs when it is late

AS 398 often beats the schedule: 117 of 341 completed flights, 34%, arrived 15 minutes or more early. The 53 late arrivals split 22 under half an hour, 20 between 30 and 60 minutes, and 11 an hour or more.

15+ min early117 flights34.3%
Within 15 min171 flights50.1%
15–29 min late22 flights6.5%
30–59 min late20 flights5.9%
1–2 hours late8 flights2.3%
2+ hours late3 flights0.9%

Scale runs 0% to 100%.

Share of 341 completed flights by arrival against schedule.

A late pushback is often recovered here: of 90 departures that left 15 minutes late or more, 46 still arrived on time. 9 flights left on time and still arrived late.

The worst days

Worst days for AS 398

The latest arrival of the period was on 22 June 2026, 10 hours 6 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across June, September and March, with no single month standing out.

The latest arrivals of AS 398 in the period
Date	Arrived late by	Largest filed cause
22 June 2026	10 hours 6 minutes	Carrier
10 September 2025	2 hours 38 minutes	Carrier
17 June 2026	2 hours 25 minutes	Late-arriving aircraft
13 March 2026	1 hour 58 minutes	Extreme weather
15 March 2026	1 hour 41 minutes	Late-arriving aircraft

Delay causes

Why AS 398 runs late

Carrier accounts for 48% of the 2,886 delay minutes carriers reported here, and the remaining four split what is left.

Carrier
48%
Late-arriving aircraft
36%
National Airspace System
12%
Extreme weather
4%

36% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 2,886 reported delay minutes here, that single category outweighs weather by 9 to one. The split is drawn from 2,886 delay minutes reported on AS 398.

Cancellations are rare at 0.87%, below the national 1.89% 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 3.2% land an hour or more behind schedule, against 8.3% 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.

The same number turns up on one other city pair in the data, including ANC to SEA (2), but none flew often enough under AS 398 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SEA to IAH only.

One caution: this is a thin sample. 344 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 84.5% on time with 0.87% cancelled over 344 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, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures