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Route Reliability

San Juan → Boston

SJU–BOS · 1,674 miles · Luis Muñoz Marín International Airport to Boston Logan International Airport

69
Usually Fine
WanderNerd Reliability Score
73%
Arrive within 15 minutes
11 min
Average arrival delay
2.7%
Cancelled
2,028
Flights in the data

Data through May 2026.

Who flies it best

Ranked by on-time arrivals. Historical results, not predictions.

  1. 1.Delta Air Lines80%398 flights
  2. 2.Spirit Airlines75%159 flights
  3. 3.JetBlue Airways71%1,437 flights

Not enough history to rank: Frontier Airlines (34 flights). We rank airlines only after 100 flights on the route.

What the data says

Morning-you made the right choice.

SJU–BOS flights departing between 3–6 AM arrived on time 88% of the time, versus 63% between 3–6 PM.

Skip Thursday if you can.

SJU–BOS flights arrived on time 80% of the time on Tuesdays. On Thursdays: 70%.

Delta Air Lines runs this route best.

Delta Air Lines arrived on time 80% of the time on this route; JetBlue Airways managed 71%.

Trending in the right direction.

SJU–BOS flights arrived on time 77% of the time over the last three months in the data, compared with 66% in the three months before that.

Best historical flights

Ranked by on-time arrivals, minimum 100 flights. Past performance, not a promise.

Top flights by on-time rate

More flights on this route

The breakdown

On-time by weekday
  • Mon73%(276 flights)
  • Tue80%(255 flights)
  • Wed73%(244 flights)
  • Thu70%(299 flights)
  • Fri76%(282 flights)
  • Sat72%(319 flights)
  • Sun71%(292 flights)
On-time by departure window
  • 12–3 AM84%(25 flights)
  • 3–6 AM88%(89 flights)
  • 6–9 AM80%(328 flights)
  • 9 AM–12 PM81%(148 flights)
  • 12–3 PM76%(707 flights)
  • 3–6 PM63%(344 flights)
  • 6–9 PM64%(289 flights)
  • 9 PM–12 AM65%(37 flights)
On-time trend by month
82%
May

Jun 85% → May 82% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202585%163
July 202575%174
August 202567%181
September 202576%84
October 202574%97
November 202578%116
December 202568%185
January 202664%184
February 202668%192
March 202678%231
April 202671%215
May 202682%145

Keep nerding

Based on 2,028 historical flights, because apparently we checked. Historical flight data: U.S. Bureau of Transportation Statistics, June 2025 – May 2026. Data through May 2026. How we calculate this.