PlainFlights

Route · STL → SAN · 2020–2025 BTS data

St. Louis to San Diego

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), STL to SAN (St. Louis to San Diego) ranks #3468 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

78.3%
On-time
-0.7 pts
vs US avg
54 min
Delay when late
2,630
Flights
#3468 of 4927
Corpus placement

Cancelled

0.3%

Best Month

Sep 2024 85%

Worst Month

May 2024 65%

Distance

1,557 mi

Carriers

1

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 46 16 0 0 WN
Nov 2025 48 11 0 0 WN
Oct 2025 57 16 0 0 WN
Sep 2025 34 7 0 1 WN
Aug 2025 36 13 0 0 WN
Jul 2025 39 16 0 0 WN
Jun 2025 39 13 0 0 WN
May 2025 39 8 0 0 WN
Apr 2025 41 14 0 0 WN
Mar 2025 53 8 0 0 WN
Feb 2025 43 9 0 0 WN
Jan 2025 40 11 2 1 WN
Dec 2024 46 10 1 2 WN
Nov 2024 48 3 0 0 WN
Oct 2024 50 10 0 0 WN
Sep 2024 60 9 0 0 WN
Aug 2024 62 10 0 0 WN
Jul 2024 62 16 0 0 WN
Jun 2024 58 18 0 0 WN
May 2024 54 19 0 0 WN
Apr 2024 45 10 0 0 WN
Jan 2024 32 9 0 0 WN
Dec 2023 37 5 0 0 WN
Nov 2023 37 2 0 0 WN

STL–SAN seasonal on-time pattern

Best: February (88.5%) · weakest: July (71.1%)

70%75%80%85%90% JanFebMarAprMayJunJulAugSepOctNovDec 76.4%

Strongest calendar month

February

88.5% on-time · ~48 flights/mo

Busiest calendar month

February

~48 flights/mo avg

Weakest calendar month

July

71.1% on-time · ~47 flights/mo

Cancellation Rate

0.3%

3 of 1,106 flights

Diversion Rate

0.4%

4 of 1,106 flights

Origin-hub reliability standing

Mid-pack among STL departures

From STL, this corridor sits with 45 other 75–85% on-time routes out of 51 tracked departures, not the hub's reliability leaders (5 at ≥85%) and not the softest ( 1 below 75%). Destination: San Diego · fleet on-time rank #3765 of 4927.

What the Data Says About STL to SAN

The St. Louis to San Diego corridor (STL to SAN) posts a 78.3% on-time rate on the lower edge of the average band, based on 2,630 tracked flights. Late flights run 53.9 minutes behind on average. 1 carrier cover the 1,557-mile route; over the last 24 months, 3 of 1,106 flights were cancelled (0.3%) and 0.4% diverted.

The monthly split is wide on this route: Sep 2024 posted the strongest performance at 85% on-time, while May 2024 came in at just 65% - a 20-point swing worth factoring into travel timing.

On the multi-year calendar, STL–SAN peaks in February at 88.5% on-time ; the softest month is July at 71.1%, a 17.4-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does STL to SAN rank among US routes by traffic?
According to PlainFlights' route traffic ranking, STL to SAN ranks #3468 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 STL to SAN?
Flights from St. Louis to San Diego have a 78.3% on-time rate based on 2,630 flights. The average delay is 53.9 minutes. The best recent month was Sep 2024 with 85% on-time.
What is the cancellation rate for STL to SAN?
Over the last 24 months, 0.3% of flights on this route were cancelled (3 of 1,106 flights) and 0.4% were diverted.
How far is the flight from STL to SAN?
The flight distance from St. Louis (STL) to San Diego (SAN) is approximately 1,557 miles. This route is served by 1 carrier.
When is the best time to fly from STL to SAN?
The best recent month for on-time performance was Sep 2024 (85% on-time). The worst was May 2024 (65% 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 STL–SAN data

STL–SAN is mid-pack at 78.3% on-time; month and carrier mix move more than the corridor headline.

  • Compare STL and SAN airport profiles: delay causes and top routes differ even on the same corridor. STL airport
  • If your dates flex, February (88.5% on-time) beats July (71.1%) on this corridor. Seasonal chart
  • 4 other routes post a similar 78.3% 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.