Historical on-time performance
St. Louis to Salt Lake City
1,156 miData through May 2026Source: US DOT · BTS
Flights on STL–SLC arrive on time 87% of the time over the last 12 months.
On-time rate87%arrived within 15 min
p90 delay20 min1 in 10 flights is worse (tail risk)
Cancelled1.0%of scheduled flights
based on 978 flights over the last 12 months. On-time means arriving within 15 minutes (BTS standard).
By airline
How each carrier compares
- Delta Air LinesOn-time87%Medianon timep9020 minCancel1.0%Flights978
Why flights run late
Delay causes
- Airline55%
- Weather10%
- Air traffic (NAS)7%
- Late aircraft28%
- Security0%
Most delay minutes here are attributed to Airline.
When flights don't go
Why flights were cancelled
- Airline80%
- Weather20%
- Air traffic (NAS)0%
- Security0%
Most cancellations here are attributed to Airline. Shares are among 10 cancellations with a reported cause (BTS reports causes from June 2003).
Over time
On-time trend
By season
On-time rate by month
When to fly
Best time to fly STL → SLC
All airlines · rolling 36 months (2023-06 .. 2026-05).
Best time of day
Mornings are the most reliable time of day to fly this route — 92% on time.
- Mornings92% on time · p90 5 min · 1,095 flights
- Afternoons88% on time · p90 15 min · 800 flights
- Evenings86% on time · p90 20 min · 949 flights
Best day of week
On-time rates are fairly even by day on this route — ranging from 86% to 91% on time.
- Tuesdays91% on time · p90 10 min · 402 flights
- Wednesdays90% on time · p90 10 min · 405 flights
- Thursdays90% on time · p90 10 min · 437 flights
- Mondays88% on time · p90 15 min · 441 flights
- Saturdays87% on time · p90 20 min · 368 flights
- Fridays87% on time · p90 15 min · 437 flights
- Sundays86% on time · p90 20 min · 435 flights
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