Route profile
EWR→SEA
Flight reliability, delays and best times to fly from Newark to Seattle, 2,402 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 21% of comparable major US routes (4,598 compared)
Calculated from 6,400 flights. How this is calculated
EWR → SEA arrives on time 74.1% of the time; the return trip, SEA → EWR, arrives on time 79.3% of the time, a 5.2-point gap between the two directions of the same city pair.
EWR → SEA spends 39.1 minutes on the ground on a 2,402-mile trip: 27.0 minutes from pushback to wheels-up at EWR and 12.2 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 EWR to SEA differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
EWR to SEA struggles most at 2 PM: 63.6% of its flights scheduled then arrive on time, 11.3 points behind the 74.9% on routes of similar length at the same hour. Against all other routes the gap is 11 points.
EWR to SEA is at its best against routes of similar length for flights scheduled at 3 PM: 80.8% arrive on time, 5.5 points ahead of the 75.3% those routes manage at that hour. Against all other routes the gap is 8.1 points.
Friday is the day EWR to SEA slips furthest against routes of similar length, 70.7% on time where they average 77.4%, 6.7 points lower. Against all other routes the gap is 5.5 points.
In July, EWR to SEA runs 10.5 points below routes of similar length, 60.0% on time to 70.5%. Against all other routes the gap is 9.8 points.
United Airlines’ flights on EWR to SEA arrive on time 75.3% of the time, 6 points below the 81.3% it manages on its routes of similar length. Against all other routes the gap is 4.6 points.
EWR to SEA against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 2 PM departures | 63.6% | routes of similar length | 74.9% | −11.3 pts | 121 here, 32,108 there |
| Hour: 3 PM departures | 80.8% | routes of similar length | 75.3% | +5.5 pts | 454 here, 46,092 there |
| Weekday: Friday | 70.7% | routes of similar length | 77.4% | −6.7 pts | 924 here, 160,542 there |
| Month: July | 60.0% | routes of similar length | 70.5% | −10.5 pts | 861 here, 129,585 there |
| Airline: United Airlines | 75.3% | routes of similar length | 81.3% | −6.0 pts | 3,021 here, 238,230 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 2,402 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.
Why EWR → SEA flights are cancelled
July 2023 – July 2026
EWR → SEA cancelled 124 of 6,400 scheduled flights — about 1 in every 52. The reason filed most often was extreme weather, 57.3% of the cancellations coded on this route — about 1 in every 90 scheduled flights.
Share of cancellations
Of 124 cancelled departures carrying a reason code.
What each reason means
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
71 cancellations, 57.3% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
43 cancellations, 34.7% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
10 cancellations, 8.1% of the total.
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. With only one or two carriers on the route, the split mostly reflects how they file. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
124 coded cancellations were recorded on EWR → SEA; the section appears from 50.
When it goes wrong
July 2023 – July 2026
57 min late
against a median of 6 min early
EWR → SEA has an average that understates its risk: a typical arrival is 6 min early, but the worst tenth are 63 minutes worse than that. If the trip has something unmissable at the end of it, the median is the wrong number to plan against.
Percentiles over 6,400 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SEA after arriving from EWR.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 40% | Likely to miss |
| 45 min | 25% | High risk |
| 60 min | 17% | High risk |
| 90 min | 9.3% | Some risk |
| 120 min | 5.9% | Some 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 1.94% of the time and diverts 0.20% of the time, which a late arrival never shows up in.
Chance of missing is the share of 6,263 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 57 minutes late (90th-percentile gate arrival delay), over 6,400 operations.
Any other layover length: connection checker.
Best time to fly
EWR → SEA flights departing 9 AM–12 PM arrived on time 83.1% of the time, against 63.7% for 6–9 PM departures, a gap of 19.4 percentage points.
By departure window
By departure hour
- 12 AM to 6 AM: too few flights to score
- 7 AM: 80.7% on time from 1,544 flights
- 8 AM: 81.4% on time from 401 flights
- 9 AM: 84.2% on time from 224 flights
- 10 AM: 83.4% on time from 181 flights
- 11 AM to 1 PM: too few flights to score
- 2 PM: 63.6% on time from 123 flights
- 3 PM: 80.8% on time from 460 flights
- 4 PM: 79.5% on time from 920 flights
- 5 PM: 65.5% on time from 434 flights
- 6 PM: 66.7% on time from 1,113 flights
- 7 PM: 60.1% on time from 685 flights
- 8 PM: 60.0% on time from 214 flights
- 9 PM to 11 PM: too few flights to score
Why EWR → SEA runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s 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 EWR → SEA. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on EWR → SEA, at 41.8%: flights here mostly leave late because the plane came in late, and the day shows it: 9 AM–12 PM departures arrived on time 83.1% of the time and 6–9 PM departures 63.7%.
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 | 3,328 | 73.0% | 2.46% | -5 min | 9.4% |
| United Airlines | 3,072 | 75.3% | 1.37% | -7 min | 9.5% |
Alaska Airlines flew 52.0% of the 6,400 flights listed. Alaska Airlines cancelled 2.46% of its flights here against 1.37% for United Airlines.
United Airlines arrived on time 2.3 percentage points more often than Alaska Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
| Flight | Scheduled | Operations | On time |
|---|---|---|---|
| AS299 Alaska Airlines | 7:30 AM | 852 | 76.6% |
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Friday the least, a gap of 8.1 percentage points.
By month
- Jan: 81.2%
- Feb: 81.9%
- Mar: 70.8%
- Apr: 81.4%
- May: 76.8%
- Jun: 68.0%
- Jul: 60.0%
- Aug: 72.9%
- Sep: 83.2%
- Oct: 80.1%
- Nov: 74.9%
- Dec: 72.1%
July is historically the weakest month and September the strongest, a spread of 23.2 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 41.0% from 217 flights
- August 2023: 72.2% from 217 flights
- September 2023: 77.5% from 206 flights
- October 2023: 87.9% from 182 flights
- November 2023: 83.4% from 147 flights
- December 2023: 91.2% from 148 flights
- January 2024: 83.9% from 130 flights
- February 2024: too few flights to score (116)
- March 2024: 84.8% from 133 flights
- April 2024: 83.9% from 144 flights
- May 2024: 77.3% from 194 flights
- June 2024: 59.2% from 210 flights
- July 2024: 60.0% from 216 flights
- August 2024: 68.8% from 215 flights
- September 2024: 84.9% from 205 flights
- October 2024: 80.5% from 177 flights
- November 2024: 79.6% from 142 flights
- December 2024: 85.1% from 143 flights
- January 2025: too few flights to score (117)
- February 2025: too few flights to score (102)
- March 2025: 84.4% from 128 flights
- April 2025: 65.1% from 127 flights
- May 2025: 58.3% from 134 flights
- June 2025: 69.0% from 170 flights
- July 2025: 68.8% from 217 flights
- August 2025: 77.1% from 229 flights
- September 2025: 86.7% from 227 flights
- October 2025: 72.6% from 206 flights
- November 2025: 63.2% from 171 flights
- December 2025: 45.4% from 178 flights
- January 2026: too few flights to score (119)
- February 2026: too few flights to score (103)
- March 2026: 48.8% from 165 flights
- April 2026: 91.0% from 181 flights
- May 2026: 87.8% from 213 flights
- June 2026: 75.3% from 225 flights
- July 2026: 69.5% from 246 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 73.5% against 74.6% in the 12 months before — broadly unchanged.
Data and methodology
Calculated by FlyerIntel from 6,400 EWR → 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