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

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

Historically, 75.3% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 3,899 flights.

HISTORICAL ROUTE SIGNALGenerally reliable
75.3%arrived on time
14.4%30+ min late
1.2%cancelled
3,899scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late7.3%all scheduled flights
120+ minutes late2.4%all scheduled flights
Diverted0.3%did not reach as scheduled
Average arrival+4.8 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 morning1,17086.6%5.7%1.5%
Late morning92985.4%7.6%1.1%
Afternoon1,03271.6%16.8%1.1%
Evening76851.0%32.6%1.0%

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
Monday58777.0%13.6%3.2%
Tuesday54378.3%12.3%1.5%
Wednesday54778.4%13.2%0.5%
Thursday57970.8%19.2%0.5%
Friday59072.5%14.9%0.8%
Saturday47778.8%11.7%0.6%
Sunday57672.4%15.1%0.9%

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 Airlines1,90881.9%11.1%1.0%
Southwest Airlines91064.0%20.5%0.9%
JetBlue Airways68169.5%18.4%1.8%
Delta Air Lines40080.0%9.2%1.8%

Monthly trend

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

MonthFlightsOn time30+ minCancelled
July 202542767.2%18.5%1.2%
August 202539777.6%14.6%0.5%
September 202533372.1%20.1%0.3%
October 202534276.9%13.5%0.3%
November 202529387.4%7.5%0.3%
December 202530172.8%16.6%0.7%
January 202625969.9%13.5%3.9%
February 202626673.3%12.4%7.5%
March 202630075.3%14.3%0.7%
April 202628484.5%9.2%0.0%
May 202632380.5%11.1%0.3%
June 202637470.1%17.6%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.

Airline24.5%
Late aircraft44.9%
National airspace27.8%
Weather2.7%
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.