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Flight Reliability

UA 668 · United Airlines

San Juan → Houston (SJU–IAH)

87
Pretty Reliable
WanderNerd Reliability Score
82%
Arrive within 15 minutes
1 min
Average arrival delay
0.5%
Cancelled
6 min early
Median arrival delay

Based on 365 historical flights. Data through May 2026.

What the data says

12–3 PM has a slight edge.

Departures between 12–3 PM arrived on time 85% of the time, against 78% between 3–6 PM.

Sunday scaries are real for this one.

UA 668 arrived on time 87% of the time on Tuesdays. On Sundays: 77%.

A bit behind the SJU–IAH route.

UA 668 arrived on time 82% of the time, versus 88% across the SJU–IAH route.

A bit ahead of the United Airlines network.

UA 668 arrived on time 82% of the time, versus 79% across the United Airlines network.

The breakdown

On-time by weekday
  • Mon79%(52 flights)
  • Tue87%(52 flights)
  • Wed83%(52 flights)
  • Thu83%(52 flights)
  • Fri85%(52 flights)
  • Sat84%(50 flights)
  • Sun77%(52 flights)
On-time by departure window
  • 12–3 PM85%(238 flights)
  • 3–6 PM78%(124 flights)
On-time trend by month
84%
May

Jun 93% → May 84% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202593%30
July 202593%30
August 202584%31
September 202593%30
October 202565%31
November 202573%30
December 202584%31
January 202673%30
February 202685%27
March 202684%31
April 202677%30
May 202684%31
Departures on time
82%
Diverted
0.3%
Flights flown
362
Months covered
12

Same route, other flights

Keep nerding

Based on 365 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.