Carrier route record
ASSEA→RDU
Alaska Airlines · Seattle to Raleigh
- Flights
- 554
- Period
- September 2025 to August 2026
- Share of route
- 60%
- Carriers
- 2
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on SEA to RDU earns a B+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 7 points better than the national rate of 77.3%. When something does go wrong the average delay runs roughly 40 minutes. That rests on 554 flights, with a median arrival 7 minutes early.
Set against the rest of the country, Alaska's SEA to RDU record is 7 points better than the US average of 77.3%. That gap is worth roughly 72 fewer late arrivals for every thousand flights.
Key figures
On time
84.5%
Arrivals under 15 minutes late, of 550 completed flights
Avg delay
38 min
Across delayed arrivals only, not all flights
Cancelled
0.36%
National rate is 1.89%
Whole route
81.4%
Every carrier on SEA to RDU, 918 flights
These figures cover 554 flights between September 2025 and August 2026. The median arrival is 7 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.
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Carrier by carrier
Alaska against every carrier on SEA to RDU
Alaska flew 554 of the 918 flights on SEA to RDU, most of the route. Its 84.5% on time is 3 points better than the route as a whole, which runs 81.4%. Ranked by on-time rate it is first of two carriers on the route, where the range runs from Alaska at 84.5% to Delta at 76.5%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Alaska Airlines (this page) | 554 | 84.5% | 38 min | 0.36% | B+ |
| Delta Air Linesthin sample | 364 | 76.5% | 50 min | 1.37% | B |
Flight by flight
Alaska flight numbers on SEA to RDU
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.
Departure window
When Alaska runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 554 flights.
- 5am–8am—
- 8am–11am364 flights85.3%
- 11am–2pm—
- 2pm–5pm—
- 5pm–8pm—
- 8pm–5am190 flights83.2%
Scale runs 75% to 90%. Rows with fewer than 30 flights show a dash.
The 8am–11am window is the strongest at 85.3% on time. The full set of windows spans 2 points.
Across the year
Alaska on SEA to RDU through the year
October is the best month on the calendar at 93.9% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. May was the busiest month here, with 62 flights.
Across the week, Wednesday is the strongest day at 90.0% on time and Thursday the weakest at 77.8%, a spread of 12 points.
Arrival by arrival
How late Alaska on SEA to RDU runs when it is late
Alaska on SEA to RDU often beats the schedule: 189 of 550 completed flights, 34%, arrived 15 minutes or more early. Most of the lateness is short. 43 of the 85 late arrivals were under half an hour behind, and 13 reached an hour or more.
- 15+ min early189 flights34.4%
- Within 15 min276 flights50.2%
- 15–29 min late43 flights7.8%
- 30–59 min late29 flights5.3%
- 1–2 hours late11 flights2.0%
- 2+ hours late2 flights0.4%
Scale runs 0% to 100%.
Share of 550 completed flights by arrival against schedule.
A late pushback is often recovered here: of 122 departures that left 15 minutes late or more, 59 still arrived on time. 22 flights left on time and still arrived late.
The worst days
Worst days for Alaska on SEA to RDU
The latest arrival of the period was on 10 December 2025, 3 hours 25 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 |
|---|---|---|
| 10 December 2025 | 3 hours 25 minutes | Late-arriving aircraft |
| 13 March 2026 | 2 hours 53 minutes | Extreme weather |
| 29 March 2026 | 1 hour 42 minutes | National Airspace System |
| 1 August 2026 | 1 hour 26 minutes | Late-arriving aircraft |
| 16 April 2026 | 1 hour 25 minutes | Late-arriving aircraft |
Delay causes
Why Alaska runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 3,267 reported delay minutes.
- 36%Carrier
- 33%Late-arriving aircraft
- 27%National Airspace System
- 3%Extreme weather
The largest share of delay minutes, 36%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,177 of the 3,267 delay minutes reported here. The split is drawn from 3,267 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 85.3% on time here.
Cancellations are rare at 0.36%, 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 stage length
What a delay here costs
Badly late arrivals are rare here: only 2.4% land an hour or more behind schedule, against 8.3% 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.
At 2,354 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 return leg is a different operation and performs like one: it runs 74.9% on time across 554 flights, 10 points below this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 10 points of difference.
One caution: this is a thin sample. 554 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 Alaska on SEA to RDU
Put together: treat all of this as provisional. 554 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 84.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 550 completed flights over 12 months sit behind that.
Related
Where to go next
- SEA to RDU, every carrier
- Alaska on RDU to SEA, the return leg
- Delta Air Lines on SEA to RDU76.5%
- Alaska Airlines network-wide record
- Seattle-Tacoma International (SEA) delay statistics
- Raleigh-Durham International (RDU) delay statistics
- Why the first flight of the morning is statistically safest
- Worst months to fly in the US, ranked by the data
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.