PlainFlights

Route · EWR → SEA · 2020–2025 BTS data

Newark to Seattle

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), EWR to SEA (Newark to Seattle) ranks #1092 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

76.4%
On-time
-2.6 pts
vs US avg
74 min
Delay when late
10,549
Flights
#1092 of 4927
Corpus placement

Cancelled

2.0%

Best Month

Feb 2024 92%

Worst Month

Dec 2025 47%

Distance

2,402 mi

Carriers

4

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 178 95 3 1 AS,UA
Nov 2025 171 60 8 0 UA,AS
Oct 2025 206 55 4 1 AS,UA
Sep 2025 227 30 2 0 UA,AS
Aug 2025 229 52 2 0 UA,AS
Jul 2025 217 65 8 1 AS,UA
Jun 2025 170 52 2 0 AS,UA
May 2025 134 55 2 0 AS,UA
Apr 2025 127 44 1 0 UA,AS
Mar 2025 128 20 0 0 AS,UA
Feb 2025 102 29 1 1 AS,UA
Jan 2025 117 24 2 0 AS,UA
Dec 2024 143 21 2 0 AS,UA
Nov 2024 142 29 0 0 UA,AS
Oct 2024 177 34 1 2 UA,AS
Sep 2024 205 31 0 0 UA,AS
Aug 2024 215 63 11 2 AS,UA
Jul 2024 216 84 5 1 AS,UA
Jun 2024 210 84 4 0 AS,UA
May 2024 194 44 0 0 AS,UA
Apr 2024 144 23 1 0 AS,UA
Mar 2024 133 20 1 0 AS,UA
Feb 2024 116 9 1 1 AS,UA
Jan 2024 130 18 18 0 AS,UA

EWR–SEA seasonal on-time pattern

Best: September (84.9%) · weakest: July (63.5%)

60%65%70%75%80%85%90% JanFebMarAprMayJunJulAugSepOctNovDec 69.4%

Strongest calendar month

September

84.9% on-time · ~180 flights/mo

Busiest calendar month

August

~187 flights/mo avg

Weakest calendar month

July

63.5% on-time · ~185 flights/mo

Cancellation Rate

2.0%

79 of 4,031 flights

Diversion Rate

0.2%

10 of 4,031 flights

Explore origin & destination

On-time and delay data for the airports this route connects.

EWR - Newark

Full on-time, delay-cause, and seasonal performance for Newark, NJ.

EWR on-time profile

SEA - Seattle

Full on-time, delay-cause, and seasonal performance for Seattle, WA.

SEA on-time profile

Compare the two airports

See EWR and SEA side by side on delays, cancellations, and reliability.

Compare EWR vs SEA

Origin-hub reliability standing

Mid-pack among EWR departures

From EWR, this corridor sits with 60 other 75–85% on-time routes out of 74 tracked departures, not the hub's reliability leaders (5 at ≥85%) and not the softest ( 9 below 75%). Destination: Seattle · fleet on-time rank #4225 of 4927.

What the Data Says About EWR to SEA

The Newark to Seattle corridor (EWR to SEA) posts a 76.4% on-time rate on the lower edge of the average band, based on 10,549 tracked flights. Late flights run 73.7 minutes behind on average. 4 carriers cover the 2,402-mile route; over the last 24 months, 79 of 4,031 flights were cancelled (2.0%) and 0.2% diverted.

The monthly split is wide on this route: Feb 2024 posted the strongest performance at 92% on-time, while Dec 2025 came in at just 47% - a 46-point swing worth factoring into travel timing.

On the multi-year calendar, EWR–SEA peaks in September at 84.9% on-time while August carries the heaviest traffic (~187 flights per month) ; the softest month is July at 63.5%, a 21.4-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does EWR to SEA rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, EWR to SEA ranks #1092 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from EWR to SEA? ▼
Flights from Newark to Seattle have a 76.4% on-time rate based on 10,549 flights. The average delay is 73.7 minutes. The best recent month was Feb 2024 with 92% on-time.
What is the cancellation rate for EWR to SEA? ▼
Over the last 24 months, 2.0% of flights on this route were cancelled (79 of 4,031 flights) and 0.2% were diverted.
How far is the flight from EWR to SEA? ▼
The flight distance from Newark (EWR) to Seattle (SEA) is approximately 2,402 miles. This route is served by 4 carriers.
When is the best time to fly from EWR to SEA? ▼
The best recent month for on-time performance was Feb 2024 (92% on-time). The worst was Dec 2025 (47% on-time). Consider booking during months with historically better performance.

Airports on this route

EWR Airport

Newark
SEA Airport

Seattle
Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Read our methodology - how this data is sourced, computed, and verified.

Using EWR–SEA data

EWR–SEA is mid-pack at 76.4% on-time; month and carrier mix move more than the corridor headline.

  • Compare EWR and SEA airport profiles: delay causes and top routes differ even on the same corridor. EWR airport
  • If your dates flex, September (84.9% on-time) beats July (63.5%) on this corridor. Seasonal chart
  • 4 other routes post a similar 76.4% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.