BTS DATA COMPLETE THROUGH JUNE 2026HISTORICAL ODDS · NOT LIVE FLIGHT STATUS
DelayOddsKnow the route before you book
DEN→IAD

Denver, CO (DEN) to Washington, DC (IAD) flight delay odds

79.7% of 3,558 official scheduled DEN-to-IAD flights arrived on time; 12.5% arrived at least 30 minutes late and 0.6% were cancelled during July 2025–June 2026.

Source: U.S. Bureau of Transportation Statistics · Reporting window: July 2025–June 2026 · Updated September 16, 2026

HISTORICAL ROUTE SIGNALGenerally reliable
79.7%arrived on time
12.5%30+ min late
0.6%cancelled
3,558scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late6.5%all scheduled flights
120+ minutes late2.4%all scheduled flights
Diverted0.2%did not reach as scheduled
Average arrival+4.6 mincompleted flights

Which departure time was most reliable for DEN to IAD?

Among qualifying DEN-to-IAD departure window results, Early morning had the highest on-time rate: 92.9% of 677 flights. Evening was lowest at 59.1% across 700 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning67792.9%3.2%0.1%
Late morning88978.1%10.5%0.4%
Afternoon95082.5%11.9%0.4%
Evening70059.1%28.6%1.0%
Night34292.4%4.4%1.2%

Which weekday was most reliable for DEN to IAD?

Among qualifying DEN-to-IAD weekday results, Tuesday had the highest on-time rate: 84.3% of 502 flights. Sunday was lowest at 76.3% across 507 flights.

DayFlightsOn time30+ minCancelled
Monday52777.6%13.9%0.0%
Tuesday50284.3%9.4%0.0%
Wednesday50182.6%10.8%0.2%
Thursday52177.7%13.6%0.2%
Friday52380.9%13.6%1.0%
Saturday47778.8%12.6%0.6%
Sunday50776.3%13.2%2.0%

Which airline was most reliable for DEN to IAD?

Among qualifying DEN-to-IAD airline results, United Airlines had the highest on-time rate: 83.8% of 2,797 flights. Southwest Airlines was lowest at 64.8% across 761 flights.

AirlineFlightsOn time30+ minCancelled
United Airlines2,79783.8%9.9%0.5%
Southwest Airlines76164.8%21.8%0.9%

Which month was most reliable for DEN to IAD?

Among qualifying DEN-to-IAD month results, April 2026 had the highest on-time rate: 88.3% of 291 flights. July 2025 was lowest at 62.3% across 361 flights.

MonthFlightsOn time30+ minCancelled
July 202536162.3%23.3%1.1%
August 202533571.3%19.4%0.0%
September 202529279.1%10.3%0.0%
October 202528385.2%8.1%0.0%
November 202527586.9%6.5%0.4%
December 202530784.7%11.1%0.7%
January 202627985.7%5.7%3.9%
February 202625784.4%9.7%0.0%
March 202630075.0%17.7%0.7%
April 202629188.3%7.9%0.0%
May 202631680.4%11.7%0.0%
June 202626280.2%13.4%0.0%

What drove DEN to IAD delay minutes?

Late aircraft was the largest recorded DEN-to-IAD delay category, accounting for 49.9% of 44,076 BTS-attributed delay minutes during July 2025–June 2026.

Airline29.8%
Late aircraft49.9%
National airspace18.4%
Weather1.2%
Security0.7%
This is historical evidence, not a forecast.

Weather, schedules and operations change. For a trip you have already booked, use the airline or airport for live status.