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Route · SLC → STL · 2020–2025 BTS data

Salt Lake City to St. Louis

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), SLC to STL (Salt Lake City to St. Louis) ranks #2006 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

84.3%
On-time
+5.3 pts
vs US avg
66 min
Delay when late
6,271
Flights
#2006 of 4927
Corpus placement

Cancelled

0.4%

Best Month

Oct 2024 93%

Worst Month

Jul 2024 71%

Distance

1,156 mi

Carriers

13

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 79 16 1 0 DL
Nov 2025 83 14 0 0 DL
Oct 2025 88 11 0 0 DL
Sep 2025 82 18 1 0 DL
Aug 2025 88 17 0 0 OO,WN,DL
Jul 2025 92 18 0 0 WN,DL
Jun 2025 90 13 1 0 DL,WN
May 2025 86 15 0 0 DL
Apr 2025 76 14 0 0 DL
Mar 2025 80 9 1 1 DL
Feb 2025 65 9 0 0 DL
Jan 2025 66 15 1 1 DL
Dec 2024 73 16 0 0 DL
Nov 2024 82 10 0 0 DL
Oct 2024 84 6 0 0 DL
Sep 2024 81 7 0 0 DL
Aug 2024 86 16 0 0 DL,WN
Jul 2024 91 26 2 0 DL,WN
Jun 2024 87 12 0 0 DL,WN
May 2024 79 9 0 0 DL
Apr 2024 77 18 0 0 DL
Mar 2024 80 20 0 0 DL
Feb 2024 66 8 0 0 DL
Jan 2024 69 15 0 0 DL

SLC–STL seasonal on-time pattern

Best: October (88.1%) · weakest: December (78.1%)

75%80%85%90% JanFebMarAprMayJunJulAugSepOctNovDec 78.1%

Strongest calendar month

October

88.1% on-time · ~91 flights/mo

Busiest calendar month

August

~103 flights/mo avg

Weakest calendar month

December

78.1% on-time · ~81 flights/mo

Cancellation Rate

0.4%

7 of 1,930 flights

Diversion Rate

0.1%

2 of 1,930 flights

Explore origin & destination

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

SLC - Salt Lake City

Full on-time, delay-cause, and seasonal performance for Salt Lake City, UT.

SLC on-time profile

STL - St. Louis

Full on-time, delay-cause, and seasonal performance for St. Louis, MO.

STL on-time profile

Compare the two airports

See SLC and STL side by side on delays, cancellations, and reliability.

Compare SLC vs STL

Origin-hub reliability standing

Mid-pack among SLC departures

From SLC, this corridor sits with 31 other 75–85% on-time routes out of 85 tracked departures, not the hub's reliability leaders (54 at ≥85%) and not the softest ( 0 below 75%). Destination: St. Louis · fleet on-time rank #1490 of 4927.

What the Data Says About SLC to STL

Bureau of Transportation Statistics records show Salt Lake City to St. Louis (SLC to STL) running a 84.3% on-time rate over 6,271 tracked flights, on the stronger end of a typical domestic pairing. When flights do run late, the average delay is 65.6 minutes. The 1,156-mile corridor is served by 13 carriers, and over the last 24 months 0.4% of 1,930 flights were cancelled, 0.1% diverted.

The monthly split is wide on this route: Oct 2024 posted the strongest performance at 93% on-time, while Jul 2024 came in at just 71% - a 21-point swing worth factoring into travel timing.

On the multi-year calendar, SLC–STL peaks in October at 88.1% on-time while August carries the heaviest traffic (~103 flights per month) ; the softest month is December at 78.1%, a 10.0-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does SLC to STL rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, SLC to STL ranks #2006 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 SLC to STL? ▼
Flights from Salt Lake City to St. Louis have a 84.3% on-time rate based on 6,271 flights. The average delay is 65.6 minutes. The best recent month was Oct 2024 with 93% on-time.
What is the cancellation rate for SLC to STL? ▼
Over the last 24 months, 0.4% of flights on this route were cancelled (7 of 1,930 flights) and 0.1% were diverted.
How far is the flight from SLC to STL? ▼
The flight distance from Salt Lake City (SLC) to St. Louis (STL) is approximately 1,156 miles. This route is served by 13 carriers.
When is the best time to fly from SLC to STL? ▼
The best recent month for on-time performance was Oct 2024 (93% on-time). The worst was Jul 2024 (71% on-time). Consider booking during months with historically better performance.

Airports on this route

SLC Airport

Salt Lake City
STL Airport

St. Louis
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 SLC–STL data

SLC–STL runs 5.3 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare SLC and STL airport profiles: delay causes and top routes differ even on the same corridor. SLC airport
  • If your dates flex, October (88.1% on-time) beats December (78.1%) on this corridor. Seasonal chart
  • 4 other routes post a similar 84.3% 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.