Flight number record
AS 329
Alaska Airlines · Chicago to Seattle
- Route
- ORD → SEA
- Departs
- 10:00
- Flights
- 255
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 329, check with Alaska Airlines.
AS 329 draws a D. Roughly one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 255 flights, with a median arrival 4 minutes late.
The national on-time rate over the same period is 77.3%, so AS 329 runs 15 points behind the country as a whole. Across a thousand flights that is about 148 extra late arrivals.
Key figures
On time
62.5%
Arrivals under 15 minutes late, of 251 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
1.57%
National rate is 1.89%
1 hour+ late
13.9%
National rate is 8.3%
These figures cover 255 flights between September 2025 and August 2026. Beyond the headline rate, 13.9% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When AS 329 flies
AS 329 flies ORD to SEA without a single fixed slot. Its most common scheduled departure was 10:00, used on 100 of 255 flights, with 20:20 (47 flights) next.
- Departs 10:00100 flights39.2%
- Departs 20:2047 flights18.4%
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 10:00 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and AS 329 runs 21 points worse at 62.5%. 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 329 next to ORD to SEA
Every carrier on ORD to SEA combined arrived on time 67.5% of the time across 5,542 flights, so AS 329 is 5 points behind it. Alaska flew 1,778 flights on the same city pair under all its flight numbers, including this one, and those ran 65.4% on time. Across its whole network Alaska Airlines managed 79.7%, which this flight trails by 17 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 329thin sample | 255 | 62.5% | 70 min | 1.57% | D |
| All Alaska Airlines on ORD–SEA | 1,778 | 65.4% | 68 min | 1.80% | C |
| All carriers on ORD–SEA | 5,542 | 67.5% | 66 min | 1.37% | C |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | B |
Across the year
AS 329 quarter by quarter
AS 329 did not run the same all year. Its best quarter was Jul–Sep 2025 at 86.7% on time and its weakest Jul–Sep 2026 at 41.3%, a swing of 45 points on roughly 64 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 flights86.7%
- Oct–Dec 202588 flights58.6%
- Jan–Mar 202621 flights—
- Apr–Jun 202669 flights67.2%
- Jul–Sep 202647 flights41.3%
Scale runs 35% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, AS 329 did best on Saturday at 70.6% on time and worst on Thursday at 50.0%. Each day rests on about 36 flights, so a gap of 21 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 329 runs when it is late
The 94 late arrivals split 28 under half an hour, 31 between 30 and 60 minutes, and 35 an hour or more.
- 15+ min early41 flights16.3%
- Within 15 min116 flights46.2%
- 15–29 min late28 flights11.2%
- 30–59 min late31 flights12.4%
- 1–2 hours late21 flights8.4%
- 2+ hours late14 flights5.6%
Scale runs 0% to 100%.
Share of 251 completed flights by arrival against schedule.
12 of 80 late departures made up the time and arrived on time, 15% of them. In the other direction, 26 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 SEA.
The worst days
Worst days for AS 329
The latest arrival of the period was on 11 June 2026, 5 hours 58 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 11 June 2026 | 5 hours 58 minutes | Late-arriving aircraft |
| 29 November 2025 | 5 hours 49 minutes | Extreme weather |
| 7 July 2026 | 4 hours 26 minutes | Carrier |
| 21 November 2025 | 3 hours 59 minutes | Late-arriving aircraft |
| 4 August 2026 | 3 hours 34 minutes | Late-arriving aircraft |
Delay causes
Why AS 329 runs late
Late-arriving aircraft accounts for 43% of the 6,608 delay minutes carriers reported here, and the remaining four split what is left.
- 43%Late-arriving aircraft
- 29%National Airspace System
- 20%Carrier
- 8%Extreme weather
43% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 6,608 reported delay minutes here, that single category outweighs weather by 6 to one. The split is drawn from 6,608 delay minutes reported on AS 329.
Cancellations sit at 1.57% against a national 1.89%, which is ordinary. Diversions add another 0.00%.
Connections and routes
What a delay on this flight costs
13.9% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 1,721 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 two other city pairs in the data, including ANC to PDX (13) and SEA to MCI (5), but none flew often enough under AS 329 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ORD to SEA only.
One caution: this is a thin sample. 255 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 329
For a booking, AS 329 is a flight to put a long connection behind. 13.9% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.
Related
Where to go next
- ORD to SEA, every carrier and departure
- SEA to ORD, the return direction
- Delta Air Lines 2041 on the same route72.8%
- Alaska Airlines 407 on the same route63.4%
- Alaska Airlines 587 on the same route65.9%
- United Airlines 2211 on the same route57.6%
- Chicago O'Hare International (ORD) delay statistics
- Seattle-Tacoma International (SEA) 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
- Why the first flight of the morning is statistically safest
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.