Skip to content
WanderNerd
Check a flight

Route Reliability

Denver → Seattle

DEN–SEA · 1,024 miles · Denver International Airport to Seattle–Tacoma International Airport

79
Usually Fine
WanderNerd Reliability Score
74%
Arrive within 15 minutes
10 min
Average arrival delay
0.7%
Cancelled
6,318
Flights in the data

Data through May 2026.

Who flies it best

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

  1. 1.United Airlines81%1,904 flights
  2. 2.Delta Air Lines78%1,088 flights
  3. 3.Alaska Airlines73%1,571 flights
  4. 4.Frontier Airlines73%412 flights
  5. 5.Southwest Airlines63%1,343 flights

What the data says

Morning-you made the right choice.

DEN–SEA flights departing between 6–9 AM arrived on time 86% of the time, versus 60% between 9 PM–12 AM.

Saturday has been the better bet.

A small edge: 77% on time on Saturdays against 71% on Thursdays.

United Airlines has a clear lead on this route.

United Airlines arrived on time 81% of the time on this route; Southwest Airlines managed 63%.

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
  • Mon74%(935 flights)
  • Tue75%(836 flights)
  • Wed75%(861 flights)
  • Thu71%(928 flights)
  • Fri72%(918 flights)
  • Sat77%(832 flights)
  • Sun74%(960 flights)
On-time by departure window
  • 12–3 AM—(2 flights)
  • 3–6 AM—(9 flights)
  • 6–9 AM86%(1682 flights)
  • 9 AM–12 PM79%(729 flights)
  • 12–3 PM79%(902 flights)
  • 3–6 PM66%(1062 flights)
  • 6–9 PM63%(1397 flights)
  • 9 PM–12 AM60%(487 flights)
On-time trend by month
77%
May

Jun 61% → May 77% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202561%636
July 202565%659
August 202566%641
September 202580%575
October 202581%548
November 202585%456
December 202561%464
January 202684%430
February 202684%401
March 202670%446
April 202685%468
May 202677%546

Same trip, other airports

Keep nerding

Based on 6,318 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.