Route profile
SEA→EWR
Flight reliability, delays and best times to fly from Seattle to Newark, 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 48% of comparable major US routes (4,598 compared)
Calculated from 6,400 flights. How this is calculated · What counts as on time
SEA → EWR arrives on time 79.3% of the time; the return trip, EWR → SEA, arrives on time 74.1% of the time, a 5.2-point gap between the two directions of the same city pair.
SEA → EWR spends 31.9 minutes on the ground on a 2,402-mile trip: 22.2 minutes from pushback to wheels-up at SEA and 9.6 minutes from touchdown to gate at EWR.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where SEA to EWR differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
SEA to EWR struggles most at 10 AM: 66.2% of its flights scheduled then arrive on time, 12 points behind the 78.2% on routes of similar length at the same hour. Against all other routes the gap is 16.6 points.
SEA to EWR is at its best against routes of similar length for flights scheduled at 6 AM: 92.5% arrive on time, 3.6 points ahead of the 88.9% those routes manage at that hour.
SEA to EWR holds up on Tuesdays better than routes of similar length do: 85.1% on time to their 81.8%, a 3.3 points lead. Against all other routes the gap is 3.5 points.
March is kinder to SEA to EWR than to routes of similar length: 85.6% on time against 79.2%, 6.4 points better. Against all other routes the gap is 7.7 points.
In May, SEA to EWR runs 4.2 points below routes of similar length, 73.6% on time to 77.8%.
SEA to EWR against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 10 AM departures | 66.2% | routes of similar length | 78.2% | −12.0 pts | 680 here, 52,142 there |
| Hour: 6 AM departures | 92.5% | routes of similar length | 88.9% | +3.6 pts | 1,207 here, 62,095 there |
| Weekday: Tuesday | 85.1% | routes of similar length | 81.8% | +3.3 pts | 886 here, 150,056 there |
| Month: March | 85.6% | routes of similar length | 79.2% | +6.4 pts | 425 here, 86,649 there |
| Month: May | 73.6% | routes of similar length | 77.8% | −4.2 pts | 538 here, 94,730 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 SEA → EWR flights are cancelled
July 2023 – July 2026
SEA → EWR cancelled 109 of 6,400 scheduled flights — about 1 in every 59. The reason filed most often was extreme weather, 58.7% of the cancellations coded on this route — about 1 in every 100 scheduled flights.
Share of cancellations
Of 109 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.
64 cancellations, 58.7% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
33 cancellations, 30.3% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
12 cancellations, 11.0% 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.
109 coded cancellations were recorded on SEA → EWR; the section appears from 50.
When it goes wrong
July 2023 – July 2026
43 min late
against a median of 9 min early
Percentiles over 6,400 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at EWR after arriving from SEA.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 34% | Likely to miss |
| 45 min | 20% | High risk |
| 60 min | 13% | Some risk |
| 90 min | 7.4% | Some risk |
| 120 min | 4.5% | 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 1.70% of the time and diverts 0.52% of the time, which a late arrival never shows up in.
Chance of missing is the share of 6,258 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 43 minutes late (90th-percentile gate arrival delay), over 6,400 operations.
Any other layover length: connection checker.
Best time to fly
SEA → EWR flights departing 5–9 AM arrived on time 90.0% of the time, against 67.9% for 3–6 PM departures, a gap of 22.1 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 92.5% on time from 1,240 flights
- 7 AM: 88.3% on time from 396 flights
- 8 AM: 83.3% on time from 319 flights
- 9 AM: 74.8% on time from 348 flights
- 10 AM: 66.2% on time from 706 flights
- 11 AM: 66.8% on time from 231 flights
- 12 PM: 75.4% on time from 477 flights
- 1 PM: 73.4% on time from 228 flights
- 2 PM: 74.5% on time from 184 flights
- 3 PM: 67.9% on time from 144 flights
- 4 PM to 8 PM: too few flights to score
- 9 PM: 77.2% on time from 617 flights
- 10 PM: 76.2% on time from 767 flights
- 11 PM: 82.1% on time from 716 flights
Departure windows with fewer than 120 flights are not scored.
Why SEA → EWR runs late
July 2023 – July 2026
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s control
the inbound aircraft was late, so this flight started late
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 SEA → EWR. 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 | 3,328 | 78.1% | 1.83% | -9 min | 6.6% |
| United Airlines | 3,072 | 80.7% | 1.56% | -10 min | 8.5% |
Alaska Airlines flew 52.0% of the 6,400 flights listed.
United Airlines arrived on time 2.6 percentage points more often than Alaska Airlines on this route.
Weekly and seasonal patterns
By day of week
Tuesday is historically the most reliable day and Thursday the least, a gap of 10.7 percentage points.
By month
- Jan: 83.2%
- Feb: 85.3%
- Mar: 85.6%
- Apr: 81.8%
- May: 73.6%
- Jun: 77.3%
- Jul: 69.6%
- Aug: 77.0%
- Sep: 80.0%
- Oct: 85.5%
- Nov: 84.3%
- Dec: 81.2%
July is historically the weakest month and March the strongest, a spread of 16.0 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 73.7% from 217 flights
- August 2023: 85.6% from 217 flights
- September 2023: 71.4% from 207 flights
- October 2023: 85.8% from 183 flights
- November 2023: 88.3% from 146 flights
- December 2023: 80.3% from 147 flights
- January 2024: 78.4% from 129 flights
- February 2024: too few flights to score (116)
- March 2024: 88.0% from 134 flights
- April 2024: 76.4% from 143 flights
- May 2024: 72.2% from 194 flights
- June 2024: 75.8% from 210 flights
- July 2024: 68.4% from 216 flights
- August 2024: 75.1% from 215 flights
- September 2024: 80.4% from 205 flights
- October 2024: 90.2% from 177 flights
- November 2024: 81.0% from 142 flights
- December 2024: 83.1% from 143 flights
- January 2025: too few flights to score (116)
- February 2025: too few flights to score (102)
- March 2025: 85.2% from 129 flights
- April 2025: 76.8% from 127 flights
- May 2025: 52.3% from 134 flights
- June 2025: 71.0% from 170 flights
- July 2025: 60.7% from 217 flights
- August 2025: 70.5% from 229 flights
- September 2025: 87.2% from 227 flights
- October 2025: 81.3% from 206 flights
- November 2025: 83.6% from 171 flights
- December 2025: 80.3% from 179 flights
- January 2026: too few flights to score (118)
- February 2026: too few flights to score (103)
- March 2026: 84.1% from 166 flights
- April 2026: 89.5% from 181 flights
- May 2026: 88.2% from 213 flights
- June 2026: 83.3% from 225 flights
- July 2026: 75.1% from 246 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 82.4% against 76.5% in the 12 months before — improving by 5.9 percentage points.
Data and methodology
Calculated by FlyerIntel from 6,400 SEA → EWR 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