PDX → SEA Flight Reliability

Right now

Origin · PDXNo disruption reported

Aviation weather is not currently a factor.

Updated 08:53 UTC

Portland airport profile →

Destination · SEANo disruption reported

Aviation weather is not currently a factor.

Updated 08:53 UTC

Seattle airport profile →

Route reliability

July 2023 – July 2026

Route Reliability Score

83/ 100Strong

Better than 91% of comparable major US routes (4,598 compared)

Calculated from 16,417 flights. How this is calculated

On-time arrivals

85.9%

13,981 of 16,279

Cancellation rate

0.77%

127 cancelled

Median arrival delay

-7 min

Average 1.2 min

Severe delays

3.8%

60+ minutes late

Delay when late

61 min

Average, when 15+ min late

Flights analyzed

16,417

3 carriers

PDX → SEA arrives on time 85.9% of the time; the return trip, SEA → PDX, arrives on time 80.7% of the time, a 5.2-point gap between the two directions of the same city pair.

PDX → SEA spends 30.5 minutes on the ground on a 129-mile trip: 18.8 minutes from pushback to wheels-up at PDX and 11.7 minutes from touchdown to gate at SEA.

Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026

What stands out

Every day of the week performs about the same on this route, steadier than 97% of 4,467 comparable routes.

87.8% on time on the best day (Saturday) against 84.1% on the worst (Friday).

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 4,467 in the comparison.

Why PDX → SEA flights are cancelled

July 2023 – July 2026

PDX → SEA cancelled 127 of 16,417 scheduled flights — about 1 in every 129. The reason filed most often was the airline, 52.0% of the cancellations coded on this route — about 1 in every 249 scheduled flights.

Share of cancellations

Airline52.0%

Weather35.4%

Air traffic12.6%

Security0.0%

Of 127 cancelled departures carrying a reason code.

What each reason means

The airline1 in 249

Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.

66 cancellations, 52.0% of the total.

Extreme weather1 in 365

Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.

45 cancellations, 35.4% of the total.

The air traffic system1 in 1,026

Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.

16 cancellations, 12.6% of the total.

Security—

A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.

0 cancellations, 0.0% of the total.

Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.

127 coded cancellations were recorded on PDX → SEA; the section appears from 50.

When it goes wrong

July 2023 – July 2026

One arrival in ten is worse than

22 min late

against a median of 7 min early

Arrived an hour or more late3.8%

Typical delay when late61 min

Cancelled0.77%

Landed somewhere else0.07%

Percentiles over 16,417 operations; cancelled and diverted flights are counted separately.

Will your connection be tight enough?

Layovers at SEA after arriving from PDX.

Connection buffer and chance of missing by layover length, PDX → SEA arrivals
Connection time	Chance of missing	Reads as
30 min	32%	Likely to miss
45 min	13%	Some risk
60 min	7.4%	Some risk
90 min	3.7%	Low risk
120 min	2.4%	Low risk

This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.77% of the time and diverts 0.07% of the time, which a late arrival never shows up in.

Chance of missing is the share of 16,279 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.

The worst tenth of arrivals on this route land at least 22 minutes late (90th-percentile gate arrival delay), over 16,417 operations.

Any other layover length: connection checker.

Best time to fly

PDX → SEA flights departing 5–9 AM arrived on time 92.0% of the time, against 77.7% for 6–9 PM departures, a gap of 14.3 percentage points.

By day and hour

On-time arrival rate for each weekday and scheduled departure hour, in local time at the departure airport (PDX).

Hour of departure matters more than day of the week: hourly averages sit a typical 5.1 points from the route-wide rate, weekday averages 1.3 points.

On-time arrival rate for PDX to SEA by weekday and scheduled departure hour, local time. Each button reads out one slot.
Hour	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
5 AM–6 AM
6 AM–7 AM
7 AM–8 AM
8 AM–9 AM
9 AM–10 AM
10 AM–11 AM
11 AM–12 PM
12 PM–1 PM
1 PM–2 PM
2 PM–3 PM
3 PM–4 PM
4 PM–5 PM
5 PM–6 PM
6 PM–7 PM
7 PM–8 PM

On-time rate, % · stronger color, fewer on time

72–75
76–79
80–83
84–87
88–91
92–95
96–99

Fewer than 120 flights, not scored

Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · On time is arrival within 15 minutes of schedule. Cells round to whole percentages; the table shows one decimal.

No slot is named best or worst: too few reach 500 flights. Departures after 8 PM (637 flights) are not drawn: no slot in those hours has enough flights to score.

View as tableHide table

On-time arrival rate (%) with flights beneath, by scheduled departure hour and weekday for PDX to SEA. A dash means fewer than 120 flights, which are not scored.
Hour	Monday	Tuesday	Wednesday	Thursday	Friday	Saturday	Sunday
5 AM–6 AM	93.4% on time276 flights	92.5% on time266 flights	93.4% on time273 flights	96.0% on time277 flights	95.5% on time269 flights	93.2% on time236 flights	94.7% on time267 flights
6 AM–7 AM	90.9% on time165 flights	94.2% on time154 flights	93.6% on time172 flights	94.3% on time176 flights	89.0% on time165 flights	93.2% on time133 flights	91.7% on time171 flights
7 AM–8 AM	90.7% on time274 flights	89.8% on time277 flights	88.3% on time276 flights	89.9% on time279 flights	88.2% on time273 flights	92.4% on time270 flights	90.2% on time269 flights
8 AM–9 AM	46 flights, too few to score	52 flights, too few to score	52 flights, too few to score	50 flights, too few to score	44 flights, too few to score	54 flights, too few to score	54 flights, too few to score
9 AM–10 AM	84.6% on time189 flights	86.2% on time188 flights	81.8% on time193 flights	74.3% on time193 flights	79.9% on time186 flights	82.8% on time181 flights	78.3% on time177 flights
10 AM–11 AM	87.9% on time140 flights	87.2% on time133 flights	80.3% on time133 flights	85.5% on time138 flights	86.1% on time138 flights	86.6% on time127 flights	86.4% on time125 flights
11 AM–12 PM	85.2% on time169 flights	89.0% on time173 flights	90.2% on time176 flights	82.9% on time165 flights	80.1% on time157 flights	86.9% on time162 flights	83.4% on time151 flights
12 PM–1 PM	47 flights, too few to score	45 flights, too few to score	42 flights, too few to score	46 flights, too few to score	49 flights, too few to score	35 flights, too few to score	41 flights, too few to score
1 PM–2 PM	79.3% on time239 flights	85.4% on time233 flights	85.2% on time232 flights	79.2% on time231 flights	82.1% on time230 flights	84.2% on time219 flights	81.8% on time223 flights
2 PM–3 PM	88 flights, too few to score	89 flights, too few to score	92 flights, too few to score	89 flights, too few to score	88 flights, too few to score	75 flights, too few to score	97 flights, too few to score
3 PM–4 PM	86.4% on time199 flights	81.8% on time200 flights	85.5% on time194 flights	85.3% on time198 flights	81.6% on time201 flights	88.2% on time179 flights	80.7% on time193 flights
4 PM–5 PM	55 flights, too few to score	49 flights, too few to score	54 flights, too few to score	49 flights, too few to score	56 flights, too few to score	37 flights, too few to score	61 flights, too few to score
5 PM–6 PM	84.0% on time238 flights	85.2% on time231 flights	87.9% on time234 flights	81.8% on time233 flights	83.0% on time232 flights	91.0% on time213 flights	82.4% on time240 flights
6 PM–7 PM	23 flights, too few to score	23 flights, too few to score	20 flights, too few to score	20 flights, too few to score	20 flights, too few to score	16 flights, too few to score	20 flights, too few to score
7 PM–8 PM	78.9% on time173 flights	83.5% on time172 flights	76.1% on time167 flights	80.9% on time175 flights	72.5% on time175 flights	81 flights, too few to score	75.2% on time155 flights

By departure window

5–9 AM92.0%

9 AM–12 PM83.9%

12–3 PM83.8%

3–6 PM83.8%

6–9 PM77.7%

9 PM–5 AM84.7%

By departure hour

12 AM

3 AM

6 AM

9 AM

12 PM

3 PM

6 PM

9 PM

Why PDX → SEA runs late

July 2023 – July 2026

The airline47.0%

crew, maintenance, boarding and fueling, all within the carrier’s control

Late-arriving aircraft20.2%

the inbound aircraft was late, so this flight started late

Weather16.7%

weather severe enough to stop this flight specifically

Air traffic control15.9%

airspace and airport capacity, including weather-driven flow control

Security0.2%

screening or terminal security incidents

Share of the delay minutes US DOT attributed to each cause for PDX → SEA. Only delays of 15 minutes or more are attributed.

How this route holds up in bad weather

July 2023 – July 2026

Bad weather raises cancellations by a similar amount at both ends of PDX to SEA: 2.2 times the normal rate at PDX and 1.9 times at SEA. Cancelled in bad weather against normal hours: PDX 1.7% against 0.8%, SEA 1.5% against 0.8%. Flights that did leave SEA in bad weather arrived on time 75.4% of the time, against 79.3% in normal hours.

Bad weather and normal hours at the airports

Scheduled departures, July 2023 – July 2026

Departures from PDX and SEA in hours of bad weather and in normal hours
Departures from	PDX	SEA
Cancelled in bad weather	1.7%	1.5%
Cancelled in normal hours	0.8%	0.8%
Arrived on time, bad weather	84.6%	75.4%
Arrived on time, normal hours	83.0%	79.3%
Departures in bad weather	11,286	43,416

Of the carriers on this route, Delta Air Lines (0.8% cancelled against 1.9% for the other carriers at PDX) cancelled the fewest departures from PDX in bad weather and Alaska Airlines (2.1% cancelled against 1.2% for the other carriers at PDX) the most.

This route’s airlines in bad weather at PDX

All departures from PDX

Cancellation rates in bad weather at PDX for the airlines that fly PDX to SEA, against the other carriers at PDX in the same months
Airline	Bad-weather departures	Cancelled	Other carriers
Delta Air Lines	1,278	0.8%below the others	1.9%
SkyWest Airlines	1,681	2.4%about level	2.0%
Alaska Airlines	4,003	2.1%above the others	1.2%

These are airport figures, not route figures: every scheduled departure from PDX and SEA, to any destination, in hours the weather report called bad. The airline rows count each carrier’s departures from PDX on every route.

Weather source and limits. In full: PDX (airlines), SEA, What Weather Costs Each Airport, Who Cancels More When the Weather Turns, Airports That Change Places When Weather Turns.

Airlines on this route

Carriers with at least 200 flights, by the airline that operated each one.

Airlines on this route
Carrier	Flights	On time	Cancelled	Median delay	Severe
SkyWest Airlines	10,295	85.1%	0.48%	-7 min	4.2%
Alaska Airlines	4,902	86.0%	1.51%	-5 min	3.0%
Delta Air Lines	1,220	92.3%	0.33%	-10 min	2.8%

SkyWest Airlines flew 62.7% of the 16,417 flights listed. Alaska Airlines cancelled 1.51% of its flights here against 0.33% for Delta Air Lines.

Delta Air Lines arrived on time 7.2 percentage points more often than SkyWest Airlines on this route.

Flights on this route

Flight numbers with at least 600 operations here and still on the schedule.

Flights on this route
Flight	Scheduled	Operations	On time
OO3953 SkyWest Airlines	9:15 AM	943	85.3%
OO3802 SkyWest Airlines	1:36 PM	842	85.3%

Weekly and seasonal patterns

By day of week

Mon85.7%

Tue87.4%

Wed86.9%

Thu84.7%

Fri84.1%

Sat87.8%

Sun84.8%

Saturday is historically the most reliable day and Friday the least, a gap of 3.7 percentage points.

By month

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

June is historically the weakest month and October the strongest, a spread of 10.0 percentage points.

Reliability over time

July 2023 – July 2026

24

25

26

Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 85.4% against 84.7% in the 12 months before — broadly unchanged.

Data and methodology

Calculated by FlyerIntel from 16,417 PDX → SEA flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.

Full methodology · Data sources · Report a problem

Analysis last recomputed September 26, 2026

PDX airport SEA airport Return direction SEA → PDX

PDX→SEA

Right now

Route reliability

What stands out

Why PDX → SEA flights are cancelled

Share of cancellations

What each reason means

When it goes wrong

Will your connection be tight enough?

Best time to fly

By day and hour

By departure window

By departure hour

Why PDX → SEA runs late

How this route holds up in bad weather

Bad weather and normal hours at the airports

This route’s airlines in bad weather at PDX

Airlines on this route

Flights on this route

Weekly and seasonal patterns

By day of week

By month

Reliability over time

Data and methodology