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

Boston, MA (BOS) to San Antonio, TX (SAT) flight delay odds

Historically, 78.0% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 355 flights.

HISTORICAL ROUTE SIGNALGenerally reliable
78.0%arrived on time
13.0%30+ min late
2.3%cancelled
355scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late8.2%all scheduled flights
120+ minutes late4.2%all scheduled flights
Diverted0.3%did not reach as scheduled
Average arrival+3.5 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
Late morning31477.1%14.3%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
Monday5276.9%13.5%9.6%
Tuesday5377.4%17.0%0.0%
Wednesday5282.7%7.7%1.9%
Thursday4977.6%6.1%2.0%
Friday4977.6%18.4%2.0%
Saturday4981.6%10.2%0.0%
Sunday5172.5%17.6%0.0%

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
Delta Air Lines35578.0%13.0%2.3%

Monthly trend

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

MonthFlightsOn time30+ minCancelled
July 20253086.7%10.0%0.0%
August 20253090.0%10.0%0.0%
September 20253083.3%10.0%0.0%
October 20253076.7%16.7%0.0%
November 20252875.0%14.3%3.6%
December 20252864.3%25.0%3.6%
January 20262975.9%17.2%3.4%
February 20262867.9%10.7%3.6%
March 20263196.8%3.2%0.0%
April 20263080.0%10.0%3.3%
May 20263174.2%9.7%3.2%
June 20263063.3%20.0%6.7%

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.

Airline55.9%
Late aircraft28.3%
National airspace15.2%
Weather0.5%
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.