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

Washington, DC (IAD) to Boston, MA (BOS) flight delay odds

75.8% of 1,462 official scheduled IAD-to-BOS flights arrived on time; 15.7% arrived at least 30 minutes late and 1.9% 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
75.8%arrived on time
15.7%30+ min late
1.9%cancelled
1,462scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late9.2%all scheduled flights
120+ minutes late4.0%all scheduled flights
Diverted0.0%did not reach as scheduled
Average arrival+9.6 mincompleted flights

Which departure time was most reliable for IAD to BOS?

Among qualifying IAD-to-BOS departure window results, Early morning had the highest on-time rate: 91.4% of 233 flights. Evening was lowest at 58.4% across 365 flights.

Departure windowFlightsOn time30+ minCancelled
Early morning23391.4%4.3%0.4%
Late morning11187.4%5.4%3.6%
Afternoon39776.1%15.9%1.0%
Evening36558.4%29.9%3.0%
Night35679.5%11.8%2.2%

Which weekday was most reliable for IAD to BOS?

Among qualifying IAD-to-BOS weekday results, Saturday had the highest on-time rate: 84.9% of 205 flights. Monday was lowest at 69.5% across 213 flights.

DayFlightsOn time30+ minCancelled
Monday21369.5%17.4%4.2%
Tuesday20576.1%15.6%1.0%
Wednesday20477.5%13.7%1.5%
Thursday21172.0%21.8%1.4%
Friday21379.8%15.0%0.5%
Saturday20584.9%9.3%0.5%
Sunday21171.1%17.1%4.3%

Which airline was most reliable for IAD to BOS?

Only United Airlines met the IAD-to-BOS airline threshold: 75.9% of 1,459 scheduled flights arrived on time during July 2025–June 2026.

AirlineFlightsOn time30+ minCancelled
United Airlines1,45975.9%15.6%1.9%
Republic Airways333.3%66.7%0.0%

Which month was most reliable for IAD to BOS?

Among qualifying IAD-to-BOS month results, January 2026 had the highest on-time rate: 82.0% of 111 flights. September 2025 was lowest at 57.0% across 142 flights.

MonthFlightsOn time30+ minCancelled
July 202512469.4%25.0%1.6%
August 202513479.9%14.2%0.0%
September 202514257.0%30.3%1.4%
October 202512473.4%21.0%0.8%
November 202511976.5%12.6%1.7%
December 202512276.2%16.4%0.0%
January 202611182.0%7.2%6.3%
February 202610379.6%8.7%7.8%
March 202611979.0%16.8%1.7%
April 202612080.8%11.7%0.0%
May 202612480.6%8.1%0.8%
June 202612079.2%12.5%2.5%

What drove IAD to BOS delay minutes?

National airspace was the largest recorded IAD-to-BOS delay category, accounting for 56.1% of 23,833 BTS-attributed delay minutes during July 2025–June 2026.

Airline17.7%
Late aircraft19.8%
National airspace56.1%
Weather6.3%
Security0.0%
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.