Flight number record
AS 438
Alaska Airlines · Seattle to Houston
- Route
- SEA → IAH
- Departs
- 10:52
- Flights
- 363
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 438, check with Alaska Airlines.
AS 438 sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.3%. The late ones land roughly 45 minutes behind schedule. That rests on 363 flights, with a median arrival 3 minutes late.
The national on-time rate over the same period is 77.3%, so AS 438 runs 7 points behind the country as a whole. Across a thousand flights that is about 67 extra late arrivals.
Key figures
On time
70.6%
Arrivals under 15 minutes late, of 360 completed flights
Avg delay
44 min
Across delayed arrivals only, not all flights
Cancelled
0.28%
National rate is 1.89%
1 hour+ late
4.2%
National rate is 8.3%
These figures cover 363 flights between September 2025 and August 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.
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Schedule
When AS 438 flies
AS 438 flies SEA to IAH without a single fixed slot. Its most common scheduled departure was 10:52, used on 70 of 363 flights, with 11:52 (52 flights) next.
- Departs 10:5270 flights19.3%
- Departs 11:5252 flights14.3%
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 10:52 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and AS 438 runs 13 points worse at 70.6%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
AS 438 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 438 is 13 points behind 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 trails by 9 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 438thin sample | 363 | 70.6% | 44 min | 0.28% | C+ |
| 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 438 quarter by quarter
AS 438 did not run the same all year. Its best quarter was Jul–Sep 2025 at 80.0% on time and its weakest Oct–Dec 2025 at 53.8%, a swing of 26 points on roughly 73 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 202530 flights80.0%
- Oct–Dec 202591 flights53.8%
- Jan–Mar 202689 flights78.4%
- Apr–Jun 202691 flights76.7%
- Jul–Sep 202662 flights70.5%
Scale runs 45% to 85%.
By weekday, AS 438 did best on Wednesday at 76.9% on time and worst on Sunday at 63.5%. Each day rests on about 52 flights, so a gap of 13 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 438 runs when it is late
The 106 late arrivals split 42 under half an hour, 49 between 30 and 60 minutes, and 15 an hour or more.
- 15+ min early77 flights21.4%
- Within 15 min177 flights49.2%
- 15–29 min late42 flights11.7%
- 30–59 min late49 flights13.6%
- 1–2 hours late11 flights3.1%
- 2+ hours late4 flights1.1%
Scale runs 0% to 100%.
Share of 360 completed flights by arrival against schedule.
A late pushback is often recovered here: of 106 departures that left 15 minutes late or more, 37 still arrived on time. In the other direction, 37 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at IAH.
The worst days
Worst days for AS 438
The latest arrival of the period was on 24 November 2025, 3 hours 15 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. On four of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 24 November 2025 | 3 hours 15 minutes | National Airspace System |
| 9 March 2026 | 3 hours 7 minutes | Carrier |
| 14 July 2026 | 2 hours 39 minutes | Carrier |
| 17 February 2026 | 2 hours 31 minutes | Carrier |
| 25 October 2025 | 1 hour 59 minutes | Carrier |
Delay causes
Why AS 438 runs late
National Airspace System accounts for 43% of the 4,638 delay minutes carriers reported here, and the remaining four split what is left.
- 43%National Airspace System
- 36%Carrier
- 17%Late-arriving aircraft
- 3%Extreme weather
- 1%Security
The largest share of delay minutes, 36%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,692 of the 4,638 delay minutes reported here. The split is drawn from 4,638 delay minutes reported on AS 438.
Cancellations are rare at 0.28%, 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 4.2% 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.
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: 13 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.
Related
Where to go next
- SEA to IAH, every carrier and departure
- IAH to SEA, the return direction
- United Airlines 2135 on the same route92.8%
- Alaska Airlines 398 on the same route84.5%
- Seattle-Tacoma International (SEA) delay statistics
- George Bush Intercontinental (IAH) delay statistics
- Alaska Airlines on-time record
- Every Alaska Airlines flight number with a record
- The most and least reliable flight numbers in the US
- The best time of day to fly, according to 7.05 million flight records
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 ; recomputed monthly. How this data is collected.