Route profile
RDU→SEA
Flight reliability, delays and best times to fly from Raleigh–Durham to Seattle, 2,354 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 72% of comparable major US routes (4,598 compared)
Calculated from 2,787 flights. How this is calculated · What counts as on time
RDU → SEA arrives on time 79.5% of the time; the return trip, SEA → RDU, arrives on time 80.4% of the time.
RDU → SEA spends 30.8 minutes on the ground on a 2,354-mile trip: 17.7 minutes from pushback to wheels-up at RDU and 13.1 minutes from touchdown to gate at SEA.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where RDU to SEA differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
RDU to SEA is at its best against routes of similar length for flights scheduled at 6 PM: 72.6% arrive on time, 4.1 points ahead of the 68.5% those routes manage at that hour. Against all other routes the gap is 4 points.
RDU to SEA holds up on Saturdays better than routes of similar length do: 83.1% on time to their 78.8%, a 4.3 points lead.
July is kinder to RDU to SEA than to routes of similar length: 78.0% on time against 70.4%, 7.6 points better. Against all other routes the gap is 8.3 points.
In December, RDU to SEA runs 6 points below routes of similar length, 73.1% on time to 79.1%. Against all other routes the gap is 5.7 points.
Delta Air Lines does better on RDU to SEA than on its routes of similar length: 87.4% on time here, 81.2% there, 6.2 points apart. Against all other routes the gap is 5.9 points.
RDU to SEA against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 6 PM departures | 72.6% | routes of similar length | 68.5% | +4.1 pts | 660 here, 61,228 there |
| Weekday: Saturday | 83.1% | routes of similar length | 78.8% | +4.3 pts | 379 here, 148,345 there |
| Month: July | 78.0% | routes of similar length | 70.4% | +7.6 pts | 369 here, 131,252 there |
| Month: December | 73.1% | routes of similar length | 79.1% | −6.0 pts | 208 here, 87,594 there |
| Airline: Delta Air Lines | 87.4% | routes of similar length | 81.2% | +6.2 pts | 1,110 here, 213,394 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 2,354 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
33 min late
against a median of 6 min early
Percentiles over 2,787 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SEA after arriving from RDU.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 39% | Likely to miss |
| 45 min | 19% | High risk |
| 60 min | 11% | Some risk |
| 90 min | 4.5% | Low risk |
| 120 min | 2.8% | 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 1.00% of the time and diverts 0.39% of the time, which a late arrival never shows up in.
Chance of missing is the share of 2,748 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 33 minutes late (90th-percentile gate arrival delay), over 2,787 operations.
Any other layover length: connection checker.
Best time to fly
RDU → SEA flights departing 5–9 AM arrived on time 83.8% of the time, against 72.2% for 6–9 PM departures, a gap of 11.6 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 87.8% on time from 571 flights
- 7 AM: 81.6% on time from 1,137 flights
- 8 AM to 4 PM: too few flights to score
- 5 PM: 74.1% on time from 196 flights
- 6 PM: 72.6% on time from 672 flights
- 7 PM: 71.1% on time from 193 flights
- 8 PM to 11 PM: too few flights to score
Why RDU → SEA runs late
July 2023 – July 2026
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for RDU → SEA. Only delays of 15 minutes or more are attributed. What the five causes mean
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| Alaska Airlines | 1,663 | 74.2% | 1.26% | -1 min | 5.6% |
| Delta Air Lines | 1,124 | 87.4% | 0.62% | -12 min | 3.4% |
Alaska Airlines flew 59.7% of the 2,787 flights listed.
Delta Air Lines arrived on time 13.2 percentage points more often than Alaska Airlines on this route.
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Monday the least, a gap of 6.3 percentage points.
By month
- Jan: 79.5%
- Feb: 81.3%
- Mar: 77.0%
- Apr: 81.3%
- May: 74.3%
- Jun: 72.6%
- Jul: 78.0%
- Aug: 80.0%
- Sep: 87.3%
- Oct: 85.7%
- Nov: 88.9%
- Dec: 73.1%
June is historically the weakest month and November the strongest, a spread of 16.3 percentage points.
Reliability over time
July 2023 – July 2026
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 77.2% against 81.7% in the 12 months before — declining by 4.5 percentage points.
Data and methodology
Calculated by FlyerIntel from 2,787 RDU → 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
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed