Flight number record

AS 1311

Alaska Airlines · San Jose to Seattle

Route: SJC → SEA
Departs: 10:06
Flights: 296
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s AS 1311, check with Alaska Airlines.

AS 1311 earns an A. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 13 points better than the national rate of 77.6%. When something does go wrong the average delay runs roughly 35 minutes. That rests on 296 flights, with a median arrival 14 minutes early.

Set against the rest of the country, AS 1311's record is 13 points better than the US average of 77.6%. That gap is worth roughly 134 fewer late arrivals for every thousand flights.

On time

91.0%

Arrivals under 15 minutes late, of 288 completed flights

Avg delay

33 min

Across delayed arrivals only, not all flights

Cancelled

2.70%

National rate is 1.81%

1 hour+ late

0.7%

National rate is 8.1%

These figures cover 296 flights between July 2025 and June 2026. The median arrival is 14 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 1311 flies

AS 1311 flies SJC to SEA without a single fixed slot. Its most common scheduled departure was 10:06, used on 37 of 296 flights, with 11:00 (36 flights) and 10:03 (35 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 10:0637 flights12.5%
Departs 11:0036 flights12.2%
Departs 10:0335 flights11.8%

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 10:06 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 84.1%, and AS 1311 runs 7 points better at 91.0%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

AS 1311 next to SJC to SEA

Every carrier on SJC to SEA combined arrived on time 83.3% of the time across 4,368 flights, so AS 1311 is 8 points ahead of it. Alaska flew 1,874 flights on the same city pair under all its flight numbers, including this one, and those ran 82.0% on time. Across its whole network Alaska Airlines managed 79.1%, which this flight beats by 12 points.

AS 1311 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
AS 1311thin sample	296	91.0%	33 min	2.70%	A
All Alaska Airlines on SJC–SEA	1,874	82.0%	49 min	1.65%	B
All carriers on SJC–SEA	4,368	83.3%	52 min	0.78%	B+
Alaska Airlines, whole network	293,372	79.1%	52 min	1.28%	B

Across the year

AS 1311 quarter by quarter

AS 1311 did not run the same all year. Its best quarter was Oct–Dec 2025 at 97.4% on time and its weakest Jul–Sep 2025 at 86.7%, a swing of 11 points on roughly 74 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 202578 flights86.7%
Oct–Dec 202580 flights97.4%
Jan–Mar 202681 flights91.1%
Apr–Jun 202657 flights87.7%

Scale runs 80% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, AS 1311 ranged from 85.3% on Sunday to 95.8% on Monday. With about 42 flights behind each day, a spread of 11 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why AS 1311 runs late

One category carries most of the weight here. Late-arriving aircraft accounts for 48% of the 850 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.

Late-arriving aircraft
48%
National Airspace System
32%
Carrier
16%
Security
3%

48% 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 850 reported delay minutes here, that single category outweighs weather by 48 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 850 delay minutes reported on AS 1311.

Cancellations run at 2.70%, against 1.81% nationally. That is about one flight in 40 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 0.7% 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.

The 696 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.

The same number turns up on one other city pair in the data, including GEG to LAX (28), but none flew often enough under AS 1311 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SJC to SEA only.

One caution: this is a thin sample. 296 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 1311

For a booking, the cancellation rate is the figure to plan around on AS 1311: 2.70% of its 296 scheduled flights did not operate. A late arrival costs roughly 35 minutes, but a cancellation costs the day, so leave a later option open.

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