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Route Reliability

St. Louis → Denver

STL–DEN · 770 miles · St. Louis Lambert International Airport to Denver International Airport

80
Pretty Reliable
WanderNerd Reliability Score
76%
Arrive within 15 minutes
12 min
Average arrival delay
0.3%
Cancelled
3,636
Flights in the data

Data through May 2026.

Who flies it best

Ranked by on-time arrivals. Historical results, not predictions.

  1. 1.United Airlines77%1,213 flights
  2. 2.Frontier Airlines77%264 flights
  3. 3.Southwest Airlines75%2,159 flights

What the data says

Morning-you made the right choice.

STL–DEN flights departing between 3–6 AM arrived on time 93% of the time, versus 55% between 3–6 PM.

Wednesday has been the better bet.

A small edge: 80% on time on Wednesdays against 73% on Mondays.

Not much between United Airlines and Southwest Airlines.

On this route they all land within 75% to 77% on time. Pick on schedule and price.

It basically never cancels.

Out of 3,636 scheduled flights, only 0.3% were cancelled.

Best historical flights

Ranked by on-time arrivals, minimum 100 flights. Past performance, not a promise.

Top flights by on-time rate

More flights on this route

The breakdown

On-time by weekday
  • Mon73%(547 flights)
  • Tue78%(479 flights)
  • Wed80%(526 flights)
  • Thu75%(514 flights)
  • Fri75%(556 flights)
  • Sat76%(439 flights)
  • Sun76%(549 flights)
On-time by departure window
  • 3–6 AM93%(386 flights)
  • 6–9 AM90%(619 flights)
  • 9 AM–12 PM83%(476 flights)
  • 12–3 PM81%(705 flights)
  • 3–6 PM55%(696 flights)
  • 6–9 PM67%(597 flights)
  • 9 PM–12 AM62%(131 flights)
On-time trend by month
74%
May

Jun 67% → May 74% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202567%335
July 202566%342
August 202572%327
September 202578%325
October 202581%334
November 202584%274
December 202570%265
January 202684%249
February 202685%250
March 202674%316
April 202680%284
May 202674%309

Keep nerding

Based on 3,636 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.