Flight number record
AS 531
Alaska Airlines · Portland to Las Vegas
- Route
- PDX → LAS
- Departs
- 17:50
- Flights
- 283
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s AS 531, check with Alaska Airlines.
AS 531 lands a B+, 3 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 283 flights, with a median arrival 6 minutes early.
Key figures
On time
80.7%
Arrivals under 15 minutes late, of 280 completed flights
Avg delay
56 min
Across delayed arrivals only, not all flights
Cancelled
0.71%
National rate is 1.89%
1 hour+ late
5.4%
National rate is 8.3%
These figures cover 283 flights between September 2025 and August 2026. The median arrival is 6 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.
Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Schedule
When AS 531 flies
AS 531 flies PDX to LAS without a single fixed slot. Its most common scheduled departure was 17:50, used on 90 of 283 flights, with 17:41 (36 flights) and 17:52 (34 flights) next.
- Departs 17:5090 flights31.8%
- Departs 17:4136 flights12.7%
- Departs 17:5234 flights12.0%
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 17:50 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.0%, and AS 531 runs 13 points better at 80.7%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
Against the route
AS 531 next to PDX to LAS
Every carrier on PDX to LAS combined arrived on time 79.9% of the time across 2,934 flights, so AS 531 is about level with it. Alaska flew 1,571 flights on the same city pair under all its flight numbers, including this one, and those ran 83.2% on time. Across its whole network Alaska Airlines managed 79.7%, close to this flight's figure.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| AS 531thin sample | 283 | 80.7% | 56 min | 0.71% | B+ |
| All Alaska Airlines on PDX–LAS | 1,571 | 83.2% | 52 min | 0.45% | B+ |
| All carriers on PDX–LAS | 2,934 | 79.9% | 54 min | 0.55% | B+ |
| Alaska Airlines, whole network | 309,844 | 79.7% | 52 min | 1.20% | B |
Across the year
AS 531 quarter by quarter
AS 531 did not run the same all year. Its best quarter was Jan–Mar 2026 at 88.4% on time and its weakest Jul–Sep 2026 at 71.7%, a swing of 17 points on roughly 71 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.
- Oct–Dec 202565 flights76.9%
- Jan–Mar 202688 flights88.4%
- Apr–Jun 202670 flights82.6%
- Jul–Sep 202660 flights71.7%
Scale runs 65% to 95%.
By weekday, AS 531 did best on Tuesday at 92.7% on time and worst on Thursday at 73.8%. Each day rests on about 40 flights, so a gap of 19 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late AS 531 runs when it is late
The 54 late arrivals split 21 under half an hour, 18 between 30 and 60 minutes, and 15 an hour or more.
- 15+ min early64 flights22.9%
- Within 15 min162 flights57.9%
- 15–29 min late21 flights7.5%
- 30–59 min late18 flights6.4%
- 1–2 hours late8 flights2.9%
- 2+ hours late7 flights2.5%
Scale runs 0% to 100%.
Share of 280 completed flights by arrival against schedule.
11 of 51 late departures made up the time and arrived on time, 22% of them. In the other direction, 14 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 LAS.
The worst days
Worst days for AS 531
The latest arrival of the period was on 2 January 2026, 3 hours 24 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On four of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 2 January 2026 | 3 hours 24 minutes | Carrier |
| 20 December 2025 | 3 hours 15 minutes | Late-arriving aircraft |
| 16 July 2026 | 3 hours 3 minutes | Late-arriving aircraft |
| 9 August 2026 | 3 hours 3 minutes | Late-arriving aircraft |
| 12 June 2026 | 2 hours 46 minutes | Late-arriving aircraft |
Delay causes
Why AS 531 runs late
Late-arriving aircraft accounts for 56% of the 2,995 delay minutes carriers reported here, and the remaining four split what is left.
- 56%Late-arriving aircraft
- 24%National Airspace System
- 20%Carrier
- 1%Extreme weather
56% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 2,995 reported delay minutes here, that single category outweighs weather by 56 to one. The split is drawn from 2,995 delay minutes reported on AS 531.
Cancellations are rare at 0.71%, 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
5.4% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
The 763 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.
Every one of the 283 flights under AS 531 in the data flew PDX to LAS. 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. 283 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 531
For a booking, read AS 531 as 80.7% on time with 0.71% cancelled over 283 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- PDX to LAS, every carrier and departure
- LAS to PDX, the return direction
- Alaska Airlines 757 on the same route84.5%
- Alaska Airlines 778 on the same route82.7%
- Alaska Airlines 627 on the same route89.2%
- Portland International (PDX) delay statistics
- Harry Reid International (LAS) 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.