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Route Reliability

Chicago → Seattle

MDW–SEA · 1,733 miles · Chicago Midway International Airport to Seattle–Tacoma International Airport

69
Usually Fine
WanderNerd Reliability Score
66%
Arrive within 15 minutes
13 min
Average arrival delay
0.4%
Cancelled
673
Flights in the data

Data through May 2026.

Southwest Airlines is the only airline in this data on this route, arriving on time 66% of the time across 673 flights. No comparison to make.

What the data says

Morning flights do better here.

MDW–SEA flights departing between 6–9 AM arrived on time 77% of the time, versus 46% between 3–6 PM.

Friday is doing you no favors.

MDW–SEA flights arrived on time 75% of the time on Wednesdays and just 59% on Fridays. That gap is worth planning around.

Recent months have been rougher.

MDW–SEA flights arrived on time 60% of the time over the last three months in the data, compared with 73% in the three months before that.

Flights on this route

The breakdown

On-time by weekday
  • Mon65%(98 flights)
  • Tue67%(98 flights)
  • Wed75%(97 flights)
  • Thu61%(98 flights)
  • Fri59%(97 flights)
  • Sat72%(87 flights)
  • Sun65%(91 flights)
On-time by departure window
  • 6–9 AM77%(107 flights)
  • 9 AM–12 PM72%(192 flights)
  • 12–3 PM72%(79 flights)
  • 3–6 PM46%(85 flights)
  • 6–9 PM73%(15 flights)
  • 9 PM–12 AM61%(188 flights)
On-time trend by month
76%
May

Jun 57% → May 76% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202557%77
July 202559%86
August 202568%87
September 202580%86
October 202582%33
November 202566%29
December 202553%30
January 202687%31
February 202679%28
March 202630%57
April 202673%60
May 202676%62

Same trip, other airports

Keep nerding

Based on 673 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.