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

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

Historically, 81.2% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 1,464 flights.

HISTORICAL ROUTE SIGNALGenerally reliable
81.2%arrived on time
11.8%30+ min late
2.0%cancelled
1,464scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late6.8%all scheduled flights
120+ minutes late3.1%all scheduled flights
Diverted0.1%did not reach as scheduled
Average arrival+5.4 mincompleted flights

When is this route most reliable?

The same route can behave differently through the day. These are scheduled departure windows, not actual departure times. Small time windows with fewer than 40 flights are withheld.

Departure windowFlightsOn time30+ minCancelled
Early morning34694.8%1.7%2.0%
Late morning36589.3%5.8%1.9%
Afternoon39774.3%15.9%2.0%
Evening35667.4%23.3%2.2%

Weekday comparison

Day-of-week results use at least 30 scheduled flights per row. Look for broad patterns, not tiny percentage differences.

DayFlightsOn time30+ minCancelled
Monday21280.7%9.9%5.2%
Tuesday20783.6%10.1%1.9%
Wednesday20481.4%12.3%1.0%
Thursday21175.4%13.7%2.4%
Friday21384.0%11.7%0.5%
Saturday20686.9%8.3%0.5%
Sunday21176.8%16.6%2.8%

Airline comparison

Marketing-carrier results make codeshare flights easier to compare as travelers buy them. Dedicated route-airline reports require at least 160 flights.

AirlineFlightsOn time30+ minCancelled
United Airlines1,46181.3%11.7%2.1%
Republic Airways333.3%66.7%0.0%

Monthly trend

Month-by-month results show whether a twelve-month average hides an unusual period.

MonthFlightsOn time30+ minCancelled
July 202512470.2%23.4%1.6%
August 202513379.7%15.8%0.0%
September 202514380.4%11.2%1.4%
October 202512472.6%16.9%0.8%
November 202511985.7%9.2%1.7%
December 202512283.6%14.8%0.0%
January 202611278.6%8.0%8.0%
February 202610481.7%5.8%7.7%
March 202611985.7%9.2%2.5%
April 202612087.5%10.0%0.0%
May 202612487.9%5.6%0.8%
June 202612081.7%10.0%1.7%

What drove reported delay minutes?

BTS cause minutes are reported for qualifying delayed flights. These shares describe recorded delay minutes—not the chance that a particular cause will affect your next flight.

Airline17.7%
Late aircraft48.2%
National airspace32.1%
Weather2.0%
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.