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

Denver, CO (DEN) to Boston, MA (BOS) flight delay odds

Historically, 70.5% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 3,903 flights.

HISTORICAL ROUTE SIGNALGenerally reliable
70.5%arrived on time
20.2%30+ min late
1.2%cancelled
3,903scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late11.5%all scheduled flights
120+ minutes late4.2%all scheduled flights
Diverted0.1%did not reach as scheduled
Average arrival+12.0 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 morning43987.5%6.6%0.9%
Late morning1,12972.4%17.7%1.2%
Afternoon1,09563.6%26.8%1.5%
Evening70160.3%26.8%0.9%
Night53980.0%14.1%1.3%

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
Monday58365.9%21.8%2.6%
Tuesday54269.4%20.5%0.9%
Wednesday55472.0%21.3%0.0%
Thursday58267.9%24.2%0.7%
Friday58771.2%21.3%0.7%
Saturday46882.9%9.8%0.4%
Sunday58766.6%20.3%2.7%

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 Airlines1,91176.3%16.1%0.8%
Southwest Airlines91059.0%28.2%1.1%
JetBlue Airways68267.2%23.5%2.1%
Delta Air Lines40074.5%15.8%1.5%

Monthly trend

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

MonthFlightsOn time30+ minCancelled
July 202542765.3%26.5%1.2%
August 202539772.5%18.4%0.5%
September 202533351.1%40.2%0.6%
October 202534359.5%28.9%0.0%
November 202529279.8%12.3%0.0%
December 202530385.1%7.6%0.7%
January 202626080.8%9.2%4.6%
February 202626770.4%16.1%7.5%
March 202630074.0%18.3%0.3%
April 202628473.2%18.3%0.0%
May 202632375.5%16.1%0.3%
June 202637466.0%22.2%0.3%

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.

Airline19.1%
Late aircraft37.1%
National airspace43.0%
Weather0.9%
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.