Flight number record

AS 438

Alaska Airlines · Seattle to Houston

Route: SEA → IAH
Departs: 11:52
Flights: 363
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s AS 438, check with Alaska Airlines.

AS 438 draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is roughly 40 minutes behind schedule. Build slack into anything you connect to. That rests on 363 flights, with a median arrival 4 minutes late.

The national on-time rate over the same period is 77.6%, so AS 438 runs 11 points behind the country as a whole. Across a thousand flights that is about 110 extra late arrivals.

On time

66.6%

Arrivals under 15 minutes late, of 359 completed flights

Avg delay

42 min

Across delayed arrivals only, not all flights

Cancelled

0.83%

National rate is 1.81%

1 hour+ late

4.7%

National rate is 8.1%

These figures cover 363 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Schedule

When AS 438 flies

AS 438 flies SEA to IAH without a single fixed slot. Its most common scheduled departure was 11:52, used on 52 of 363 flights, with 11:45 (50 flights) and 11:49 (45 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 11:5252 flights14.3%
Departs 11:4550 flights13.8%
Departs 11:4945 flights12.4%

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 11:52 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and AS 438 runs 12 points worse at 66.6%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

AS 438 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 438 is 14 points behind 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%, which this flight trails by 13 points.

AS 438 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AS 438thin sample	363	66.6%	42 min	0.83%	C+
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 438 quarter by quarter

AS 438 did not run the same all year. Its best quarter was Jan–Mar 2026 at 78.4% on time and its weakest Oct–Dec 2025 at 53.8%, a swing of 25 points on roughly 91 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 flights57.8%
Oct–Dec 202591 flights53.8%
Jan–Mar 202689 flights78.4%
Apr–Jun 202691 flights76.7%

Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, AS 438 did best on Monday at 76.5% on time and worst on Friday at 58.8%. Each day rests on about 52 flights, so a gap of 18 points is worth noticing but could still narrow in another year.

Delay causes

Why AS 438 runs late

One category carries most of the weight here. National Airspace System accounts for 49% of the 5,061 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.

National Airspace System
49%
Carrier
32%
Late-arriving aircraft
18%
Security
1%

49% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 2,476 minutes out of 5,061, against a national NAS share of 21%. The split is drawn from 5,061 delay minutes reported on AS 438.

Cancellations are rare at 0.83%, 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 4.7% 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 363 flights under AS 438 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. 363 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 438

For a booking, AS 438 is one of the weaker ways to fly SEA to IAH: 14 points below the route as a whole. If the schedule allows, compare it with the other departures listed on the route page before settling on this one.

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