Best Time to Fly SLC to STL: On-Time Stats by Hour & Airline
Salt Lake City International → St Louis Lambert International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 84.5% of Salt Lake City (SLC) to St. Louis (STL) flights arrived on time (990 scheduled flights). That is 6.9 points above the national average of 77.6%.
Delta Air Lines was the only reporting airline with regular flights on this route.
Over 24 months, Tuesday was the most reliable day (89% on time) and December the worst month (79%).
The cancellation rate was 0.6% (US average 1.8%).
SLC to STL on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Delta Air Lines | 84.4% | 62 min | 0.6% | 979 |
| SkyWest Airlines | Limited data | 2 | ||
| Southwest Airlines | Limited data | 9 | ||
80%+ good 70–79.9% fair <70% poor
Best time of day to fly SLC to STL
On-time arrival % by scheduled departure hour (local time), 1,951 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | Limited data | 1 | |
| 9am–10am | 88.5% | 0.3% | 698 |
| 10am–11am | Limited data | 26 | |
| 11am–12pm | Limited data | 15 | |
| 12pm–1pm | Limited data | 7 | |
| 1pm–2pm | 87.2% | 1.2% | 166 |
| 2pm–3pm | 84.4% | 1.5% | 202 |
| 3pm–4pm | 78.7% | 0.0% | 108 |
| 5pm–6pm | 82.7% | 0.4% | 233 |
| 6pm–7pm | Limited data | 6 | |
| 8pm–9pm | 79.4% | 0.2% | 425 |
| 9pm–10pm | 84.4% | 0.0% | 64 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on SLC to STL
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 72.2% | -14.0 pts | 0.0% | 36 |
| Christmas & New Year (Dec 20 - Jan 3) | 72.9% | -13.3 pts | 1.7% | 60 |
| Summer peak (Jun 15 - Aug 15) | 80.8% | -5.4 pts | 0.5% | 369 |
| All other days | 86.2% | — | 0.4% | 1,486 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).