PlainFlights

Route · BOS → SFO · 2020–2025 BTS data

Boston to San Francisco

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), BOS to SFO (Boston to San Francisco) ranks #283 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

80.9%
On-time
+1.9 pts
vs US avg
69 min
Delay when late
21,875
Flights
#283 of 4927
Corpus placement

Cancelled

0.7%

Best Month

Jan 2025 88%

Worst Month

Apr 2024 59%

Distance

2,704 mi

Carriers

18

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 357 122 3 5 DL,AS,B6,UA
Nov 2025 361 87 9 2 UA,DL,AS,B6
Oct 2025 429 104 3 2 AS,B6,DL,UA
Sep 2025 408 76 0 0 UA,DL,AS,B6
Aug 2025 431 67 1 0 UA,AS,B6,DL
Jul 2025 450 116 1 2 AS,B6,DL,UA
Jun 2025 438 80 0 0 AS,B6,DL,UA
May 2025 432 61 1 0 AS,B6,DL,UA
Apr 2025 369 69 0 0 DL,UA,AS,B6
Mar 2025 327 61 0 1 AS,B6,DL,UA
Feb 2025 267 98 3 1 B6,DL,UA
Jan 2025 306 36 1 0 AS,B6,DL,UA
Dec 2024 377 94 2 1 AS,B6,DL,UA
Nov 2024 362 80 0 1 UA,B6,AS,DL
Oct 2024 426 68 0 1 UA,AS,DL,B6
Sep 2024 407 70 0 0 UA,AS,B6,DL
Aug 2024 427 132 4 1 AS,B6,DL,UA
Jul 2024 443 100 15 0 AS,B6,DL,UA
Jun 2024 394 136 5 2 AS,B6,DL,UA
May 2024 397 135 1 2 AS,B6,DL,UA
Apr 2024 325 132 1 0 AS,B6,DL,UA
Mar 2024 325 98 1 2 AS,B6,DL,UA
Feb 2024 276 57 4 3 AS,B6,DL,UA
Jan 2024 287 63 10 1 AS,B6,DL,UA

BOS–SFO seasonal on-time pattern

Best: October (84.5%) · weakest: December (75.9%)

74%76%78%80%82%84%86% JanFebMarAprMayJunJulAugSepOctNovDec 75.9%

Strongest calendar month

October

84.5% on-time · ~353 flights/mo

Busiest calendar month

July

~357 flights/mo avg

Weakest calendar month

December

75.9% on-time · ~295 flights/mo

Cancellation Rate

0.7%

65 of 9,021 flights

Diversion Rate

0.3%

27 of 9,021 flights

Origin-hub reliability standing

Mid-pack among BOS departures

From BOS, this corridor sits with 49 other 75–85% on-time routes out of 60 tracked departures, not the hub's reliability leaders (6 at ≥85%) and not the softest ( 5 below 75%). Destination: San Francisco · fleet on-time rank #2770 of 4927.

What the Data Says About BOS to SFO

21,875 tracked flights put the BOS to SFO pairing (Boston to San Francisco) at a 80.9% on-time rate, squarely in line with the wider network. Delays that do occur run 68.5 minutes on average. Across the 2,704-mile route and its 18 carriers, the trailing 24 months show 0.7% cancelled and 0.3% diverted (9,021 flights sampled).

The monthly split is wide on this route: Jan 2025 posted the strongest performance at 88% on-time, while Apr 2024 came in at just 59% - a 29-point swing worth factoring into travel timing.

On the multi-year calendar, BOS–SFO peaks in October at 84.5% on-time while July carries the heaviest traffic (~357 flights per month) ; the softest month is December at 75.9%, a 8.6-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does BOS to SFO rank among US routes by traffic?
According to PlainFlights' route traffic ranking, BOS to SFO ranks #283 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 BOS to SFO?
Flights from Boston to San Francisco have a 80.9% on-time rate based on 21,875 flights. The average delay is 68.5 minutes. The best recent month was Jan 2025 with 88% on-time.
What is the cancellation rate for BOS to SFO?
Over the last 24 months, 0.7% of flights on this route were cancelled (65 of 9,021 flights) and 0.3% were diverted.
How far is the flight from BOS to SFO?
The flight distance from Boston (BOS) to San Francisco (SFO) is approximately 2,704 miles. This route is served by 18 carriers.
When is the best time to fly from BOS to SFO?
The best recent month for on-time performance was Jan 2025 (88% on-time). The worst was Apr 2024 (59% on-time). Consider booking during months with historically better performance.

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 BOS–SFO data

BOS–SFO is mid-pack at 80.9% on-time; month and carrier mix move more than the corridor headline.

  • Compare BOS and SFO airport profiles: delay causes and top routes differ even on the same corridor. BOS airport
  • If your dates flex, October (84.5% on-time) beats December (75.9%) on this corridor. Seasonal chart
  • 4 other routes post a similar 80.9% 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.