Route on-time record
PDX to SEA: most on-time flights and the best time to fly
Portland (Portland International Airport) to Seattle (Seattle–Tacoma International Airport). 4,937 nonstop flights in Jun 2025 to May 2026, 84% arrived within 15 minutes and 0.7% were cancelled. The most reliable flight number was SkyWest 4008 at 5:30 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
PDX → SEA
Portland to Seattle: 4,937 nonstop flights a year
On time (12 months)
84%
Cancelled
0.7%
avg delay 10 min
Best time to leave
Before 9 AM
90% on time vs 75% 6 to 9 PM
Most reliable airline
Delta
88% chance on time
Fares open on our travel partner (Aviasales). Pick the flight number you chose here.
Most reliable nonstop flights
Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.
#1 · SkyWest 4008 · sold as United Express, Delta Connection, American Eagle or Alaska
5:30 AM → 6:38 AM1h 07m nonstop
Local times, typical schedule. Last flown 2026-05-31.
92%
chance on time
- On time (history)
- 93%
- Cancelled
- 0.0%
- Avg arrival delay
- 12 min
- Arrived on time 93% of the time (147 flights, Jun 2025 to May 2026).
- Never cancelled in 147 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 6 to 9 PM: 75%).
Moderate track record · 147 flights
Find 5:30 AM flight fares Opens this date on Aviasales#2 · Alaska 499
6:00 AM → 7:02 AM1h 02m nonstop
Local times, typical schedule. Last flown 2026-05-31.
90%
chance on time
- On time (history)
- 91%
- Cancelled
- 1.1%
- Avg arrival delay
- 5 min
- Arrived on time 91% of the time (276 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 6 to 9 PM: 75%).
Strong track record · 276 flights
Find Alaska 499 fares Opens this date on Aviasales#3 · SkyWest 3818 · sold as United Express, Delta Connection, American Eagle or Alaska
10:42 AM → 11:49 AM1h 07m nonstop
Local times, typical schedule. Last flown 2026-05-06.
89%
chance on time
- On time (history)
- 90%
- Cancelled
- 0.3%
- Avg arrival delay
- 8 min
- Arrived on time 90% of the time (323 flights, Jun 2025 to May 2026).
Strong track record · 323 flights
Find 10:42 AM flight fares Opens this date on Aviasales#4 · Delta 2360
7:05 AM → 8:09 AM1h 04m nonstop
Local times, typical schedule. Last flown 2026-05-06. Same departure also flew as Delta 1520; its record covers all of them.
88%
chance on time
- On time (history)
- 89%
- Cancelled
- 0.0%
- Avg arrival delay
- 14 min
- Arrived on time 89% of the time (76 flights, Jun 2025 to May 2026).
- Never cancelled in 76 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 6 to 9 PM: 75%).
Moderate track record · 76 flights
Find Delta 2360 fares Opens this date on Aviasales#5 · SkyWest 4023 · sold as United Express, Delta Connection, American Eagle or Alaska
11:20 AM → 12:31 PM1h 11m nonstop
Local times, typical schedule. Last flown 2026-05-31.
88%
chance on time
- On time (history)
- 88%
- Cancelled
- 0.0%
- Avg arrival delay
- 8 min
- Arrived on time 88% of the time (25 flights, Jun 2025 to May 2026).
- Short track record (25 flights), so its score leans on the airline's record at this hour.
Limited track record · 25 flights
Find 11:20 AM flight fares Opens this date on Aviasales#6 · SkyWest 3965 · sold as United Express, Delta Connection, American Eagle or Alaska
7:05 AM → 8:20 AM1h 15m nonstop
Local times, typical schedule. Last flown 2026-05-31.
88%
chance on time
- On time (history)
- 92%
- Cancelled
- 0.0%
- Avg arrival delay
- 2 min
- Arrived on time 92% of the time (25 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 90% on time; 6 to 9 PM: 75%).
- Short track record (25 flights), so its score leans on the airline's record at this hour.
Limited track record · 25 flights
Find 7:05 AM flight fares Opens this date on Aviasales#7 · SkyWest 3038 · sold as United Express, Delta Connection, American Eagle or Alaska
12:13 PM → 1:14 PM1h 01m nonstop
Local times, typical schedule. Last flown 2026-05-31.
88%
chance on time
- On time (history)
- 91%
- Cancelled
- 0.0%
- Avg arrival delay
- 15 min
- Arrived on time 91% of the time (47 flights, Jun 2025 to May 2026).
- Never cancelled in 47 scheduled flights.
- Short track record (47 flights), so its score leans on the airline's record at this hour.
Limited track record · 47 flights
Find 12:13 PM flight fares Opens this date on Aviasales#8 · SkyWest 3802 · sold as United Express, Delta Connection, American Eagle or Alaska
12:20 PM → 1:25 PM1h 05m nonstop
Local times, typical schedule. Last flown 2026-05-31.
87%
chance on time
- On time (history)
- 88%
- Cancelled
- 0.9%
- Avg arrival delay
- 7 min
- Arrived on time 88% of the time (346 flights, Jun 2025 to May 2026).
Strong track record · 346 flights
Find 12:20 PM flight fares Opens this date on Aviasales#9 · Alaska 403
9:00 AM → 10:06 AM1h 06m nonstop
Local times, typical schedule. Last flown 2026-05-12.
86%
chance on time
- On time (history)
- 94%
- Cancelled
- 1.4%
- Avg arrival delay
- 4 min
- Arrived on time 94% of the time (70 flights, Jun 2025 to May 2026).
Moderate track record · 70 flights
Find Alaska 403 fares Opens this date on Aviasales#10 · SkyWest 4062 · sold as United Express, Delta Connection, American Eagle or Alaska
3:30 PM → 4:37 PM1h 07m nonstop
Local times, typical schedule. Last flown 2026-05-31.
86%
chance on time
- On time (history)
- 90%
- Cancelled
- 0.0%
- Avg arrival delay
- 6 min
- Arrived on time 90% of the time (49 flights, Jun 2025 to May 2026).
- Never cancelled in 49 scheduled flights.
- Lands inside SEA's trouble window: 54% of its 68 ground stops and delay programs started between 4 PM and 10 PM.
- Short track record (49 flights), so its score leans on the airline's record at this hour.
Limited track record · 49 flights
Find 3:30 PM flight fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Delta Air Lines88%
342 flights · 89% on time as flown · 0.2% cancel
- SkyWest Airlines (sold as United Express, Delta Connection, American Eagle or Alaska)84%
3,492 flights · 84% on time as flown · 0.5% cancel
- Alaska Airlines81%
1,103 flights · 82% on time as flown · 1.2% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM90%
1,321 flights · avg delay 7 min
- 9 AM to noon83%
1,104 flights · avg delay 10 min
- Noon to 3 PM83%
925 flights · avg delay 11 min
- 3 to 6 PM84%
873 flights · avg delay 9 min
- 6 to 9 PM75%
533 flights · avg delay 14 min
- After 9 PM82%
181 flights · avg delay 11 min
Best day: Saturday (88%). Worst: Friday (84%).
On time by month
All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.
What delays this route
- Airline (crew, maintenance, boarding)42%
- Late-arriving aircraft27%
- Air traffic control and airport volume19%
- Severe weather10%
Share of delay minutes by the cause airlines report to the US DOT.
Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure
PDX to SEA questions
- What time of day is best to fly PDX to SEA?
- Before 9 AM: 90% of flights arrived on time, against 75% for departures 6 to 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
- Which airline is most on time from PDX to SEA?
- Delta, with a season-adjusted 88% chance of operating and arriving on time over 342 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
- What is the worst month for delays on PDX to SEA?
- June (82% on time); the best was October (90%), averaged over Jun 2023 to May 2026.
- Is this a prediction for my flight?
- No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.
More routes from PDX
- SEA to PDX (return)
- PDX to LAX 87%
- PDX to DEN 80%
- PDX to PHX 80%
- PDX to SFO 75%
- PDX to LAS 81%
- PDX to ORD 77%
- PDX to DFW 80%
- PDX to SLC 88%
- PDX to SMF 83%
- PDX to SAN 80%
- PDX to SJC 82%
- PDX to ATL 87%
Live status: FAA delays and ground stops