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Route · SEA → LWS · 2020–2025 BTS data

Seattle to Lewiston

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SEA to LWS (Seattle to Lewiston) ranks #4717 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

88.8%
On-time
+9.8 pts
vs US avg
108 min
Delay when late
734
Flights
#4717 of 4927
Corpus placement

Cancelled

0.5%

Best Month

N/A

Worst Month

N/A

Distance

261 mi

Carriers

1

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 31 2 0 0 OO
Nov 2025 30 1 0 0 OO
Oct 2025 31 2 0 0 OO
Sep 2025 30 1 0 0 OO
Aug 2025 30 3 0 0 OO
Jul 2025 31 2 0 0 OO
Jun 2025 30 4 0 0 OO
May 2025 31 3 0 0 OO
Apr 2025 30 4 0 0 OO
Mar 2025 31 5 0 0 OO
Jan 2025 31 0 0 0 OO
Dec 2024 31 2 0 0 OO
Nov 2024 30 2 0 0 OO
Oct 2024 31 3 0 0 OO
Sep 2024 30 3 0 0 OO
Aug 2024 31 7 0 0 OO
Jul 2024 31 2 0 0 OO
Jun 2024 30 6 0 0 OO
May 2024 31 7 0 0 OO
Apr 2024 30 2 0 0 OO
Mar 2024 31 4 0 0 OO
Jan 2024 31 6 2 0 OO
Dec 2023 31 4 2 0 OO
Nov 2023 30 7 0 0 OO

SEA–LWS seasonal on-time pattern

Best: July (93.5%) · weakest: June (83.3%)

80%85%90%95% JanMarAprMayJunJulAugSepOctNovDec 91.4%

Strongest calendar month

July

93.5% on-time · ~31 flights/mo

Busiest calendar month

January

~31 flights/mo avg

Weakest calendar month

June

83.3% on-time · ~30 flights/mo

Cancellation Rate

0.5%

4 of 734 flights

Diversion Rate

0.0%

0 of 734 flights

Origin-hub reliability standing

Among SEA's stronger departures

SEA → LWS posts a 88.8% on-time rate, landing in the ≥85% band with 25 of 89 BTS-tracked routes leaving Seattle. The same hub also shows 63 mid-band and 1 challenged departures · fleet-wide on-time rank #284 of 4927 (highest on-time = #1).

What the Data Says About SEA to LWS

Seattle to Lewiston (SEA to LWS) is one of the more dependable pairings in the BTS On-Time Performance dataset: a 88.8% on-time rate across 734 flights, with delays that do happen averaging 108.0 minutes. The corridor runs roughly 261 miles and is served by 1 carrier. Over the most recent 24 months, 4 of 734 flights were cancelled (0.5%) and 0 diverted (0.0%).

Monthly performance data for this route did not show a clear best/worst split in the sample window; review the monthly table above for period-by-period detail.

On the multi-year calendar, SEA–LWS peaks in July at 93.5% on-time while January carries the heaviest traffic (~31 flights per month) ; the softest month is June at 83.3%, a 10.2-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SEA to LWS rank among US routes by traffic?
According to PlainFlights' route traffic ranking, SEA to LWS ranks #4717 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 SEA to LWS?
Flights from Seattle to Lewiston have a 88.8% on-time rate based on 734 flights. The average delay is 108.0 minutes.
What is the cancellation rate for SEA to LWS?
Over the last 24 months, 0.5% of flights on this route were cancelled (4 of 734 flights) and 0.0% were diverted.
How far is the flight from SEA to LWS?
The flight distance from Seattle (SEA) to Lewiston (LWS) is approximately 261 miles. This route is served by 1 carrier.

Airports on this route

Data source

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

Using SEA–LWS data

SEA–LWS runs 9.8 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare SEA and LWS airport profiles: delay causes and top routes differ even on the same corridor. SEA airport
  • If your dates flex, July (93.5% on-time) beats June (83.3%) on this corridor. Seasonal chart
  • 4 other routes post a similar 88.8% 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.