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Route · SEA → BIL · 2020–2025 BTS data

Seattle to Billings

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SEA to BIL (Seattle to Billings) ranks #4020 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

85.8%
On-time
+6.8 pts
vs US avg
56 min
Delay when late
1,691
Flights
#4020 of 4927
Corpus placement

Cancelled

1.2%

Best Month

Apr 2021 97%

Worst Month

Dec 2022 68%

Distance

664 mi

Carriers

1

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2022 62 20 2 0 QX
Nov 2022 59 14 1 0 QX
Oct 2022 67 9 0 0 QX
Sep 2022 84 17 0 0 QX
Aug 2022 62 7 0 0 QX
Jul 2022 62 5 0 0 QX
Jun 2022 60 10 0 1 QX
May 2022 62 12 0 0 QX
Apr 2022 56 14 0 0 QX
Mar 2022 62 9 0 0 QX
Feb 2022 56 8 2 0 QX
Jan 2022 63 15 2 0 QX
Dec 2021 60 12 5 1 QX
Nov 2021 59 4 0 1 QX
Oct 2021 62 6 0 0 QX
Sep 2021 67 12 0 0 QX
Aug 2021 93 15 1 1 QX
Jul 2021 93 9 0 0 QX
Jun 2021 90 11 1 0 QX
May 2021 93 4 0 2 QX
Apr 2021 90 3 0 0 QX
Mar 2021 93 9 0 0 QX
Feb 2021 74 9 4 0 QX
Jan 2021 62 6 3 0 QX

SEA–BIL seasonal on-time pattern

Best: July (91.0%) · weakest: December (73.8%)

70%75%80%85%90%95% JanFebMarAprMayJunJulAugSepOctNovDec 73.8%

Strongest calendar month

July

91.0% on-time · ~78 flights/mo

Busiest calendar month

March

~78 flights/mo avg

Weakest calendar month

December

73.8% on-time · ~61 flights/mo

Cancellation Rate

1.2%

21 of 1,691 flights

Diversion Rate

0.4%

6 of 1,691 flights

Explore origin & destination

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

SEA - Seattle

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

SEA on-time profile

BIL - Billings

Full on-time, delay-cause, and seasonal performance for Billings, MT.

BIL on-time profile

Compare the two airports

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

Compare SEA vs BIL

Origin-hub reliability standing

Among SEA's stronger departures

SEA → BIL posts a 85.8% 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 #970 of 4927 (highest on-time = #1).

What the Data Says About SEA to BIL

Seattle to Billings (SEA to BIL) is one of the more dependable pairings in the BTS On-Time Performance dataset: a 85.8% on-time rate across 1,691 flights, with delays that do happen averaging 56.0 minutes. The corridor runs roughly 664 miles and is served by 1 carrier. Over the most recent 24 months, 21 of 1,691 flights were cancelled (1.2%) and 6 diverted (0.4%).

The monthly split is wide on this route: Apr 2021 posted the strongest performance at 97% on-time, while Dec 2022 came in at just 68% - a 29-point swing worth factoring into travel timing.

On the multi-year calendar, SEA–BIL peaks in July at 91.0% on-time while March carries the heaviest traffic (~78 flights per month) ; the softest month is December at 73.8%, a 17.2-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SEA to BIL rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, SEA to BIL ranks #4020 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 BIL? ▼
Flights from Seattle to Billings have a 85.8% on-time rate based on 1,691 flights. The average delay is 56.0 minutes. The best recent month was Apr 2021 with 97% on-time.
What is the cancellation rate for SEA to BIL? ▼
Over the last 24 months, 1.2% of flights on this route were cancelled (21 of 1,691 flights) and 0.4% were diverted.
How far is the flight from SEA to BIL? ▼
The flight distance from Seattle (SEA) to Billings (BIL) is approximately 664 miles. This route is served by 1 carrier.
When is the best time to fly from SEA to BIL? ▼
The best recent month for on-time performance was Apr 2021 (97% on-time). The worst was Dec 2022 (68% on-time). Consider booking during months with historically better performance.

Airports on this route

SEA Airport

Seattle
BIL Airport

Billings
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 SEA–BIL data

SEA–BIL runs 6.8 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 BIL airport profiles: delay causes and top routes differ even on the same corridor. SEA airport
  • If your dates flex, July (91.0% on-time) beats December (73.8%) on this corridor. Seasonal chart
  • 4 other routes post a similar 85.8% 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.