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

San Juan, PR (SJU) to Boston, MA (BOS) flight delay odds

Historically, 69.6% of scheduled reportable flights on this direction arrived on time in July 2025–June 2026. The sample includes 2,001 flights.

HISTORICAL ROUTE SIGNALVariable
69.6%arrived on time
18.7%30+ min late
2.7%cancelled
2,001scheduled flights
Based on July 2025–June 2026; on time means arrival less than 15 minutes late.
60+ minutes late10.5%all scheduled flights
120+ minutes late4.1%all scheduled flights
Diverted0.3%did not reach as scheduled
Average arrival+12.2 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 morning42078.6%10.2%1.9%
Late morning14976.5%16.1%4.0%
Afternoon1,01168.6%19.7%2.4%
Evening35058.3%27.4%4.6%
Night7171.8%16.9%1.4%

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
Monday28767.2%19.5%4.9%
Tuesday26277.1%11.8%1.1%
Wednesday24571.0%15.1%1.2%
Thursday29567.5%21.7%0.7%
Friday28474.3%17.3%1.1%
Saturday32967.8%20.7%4.3%
Sunday29963.9%23.1%5.4%

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
JetBlue Airways1,41567.7%20.7%3.0%
Delta Air Lines39876.6%12.3%1.5%
Spirit Airlines15469.5%16.9%3.9%
Frontier Airlines3467.6%17.6%2.9%

Monthly trend

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

MonthFlightsOn time30+ minCancelled
July 202517972.6%18.4%2.8%
August 202518664.5%24.7%1.1%
September 20258475.0%13.1%0.0%
October 20259873.5%17.3%1.0%
November 202512074.2%13.3%1.7%
December 202518966.1%23.8%1.6%
January 202620756.5%22.2%11.1%
February 202620761.4%22.7%7.2%
March 202623574.0%16.2%1.7%
April 202621569.8%18.1%0.0%
May 202614582.1%13.1%0.0%
June 202613678.7%12.5%0.0%

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.

Airline32.2%
Late aircraft47.2%
National airspace19.2%
Weather1.4%
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.