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Route Reliability

St. Louis → Washington

STL–IAD · 696 miles · St. Louis Lambert International Airport to Washington Dulles International Airport

70
Usually Fine
WanderNerd Reliability Score
74%
Arrive within 15 minutes
23 min
Average arrival delay
0.6%
Cancelled
717
Flights in the data

Data through May 2026.

United Airlines is the only airline in this data on this route, arriving on time 74% of the time across 717 flights. No comparison to make.

What the data says

Morning flights do better here.

STL–IAD flights departing between 6–9 AM arrived on time 79% of the time, versus 68% between 12–3 PM.

Saturday is the weak spot.

STL–IAD flights arrived on time 78% of the time on Wednesdays. On Saturdays: 70%.

Ticking up lately.

STL–IAD flights arrived on time 76% of the time over the last three months in the data, compared with 70% in the three months before that.

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
  • Mon72%(104 flights)
  • Tue76%(100 flights)
  • Wed78%(98 flights)
  • Thu73%(104 flights)
  • Fri70%(104 flights)
  • Sat70%(97 flights)
  • Sun76%(102 flights)
On-time by departure window
  • 6–9 AM79%(351 flights)
  • 12–3 PM68%(358 flights)
On-time trend by month
76%
May

Jun 63% → May 76% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202563%57
July 202574%61
August 202576%62
September 202586%58
October 202573%51
November 202573%59
December 202566%62
January 202668%59
February 202677%56
March 202673%62
April 202678%60
May 202676%62

Same trip, other airports

Keep nerding

Based on 717 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.