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Flight Reliability

UA 663 · United Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and UA 663 moved between routes during this period. Numbers below combine all of them, so treat them as background, not a verdict. For a cleaner answer, check the route you are actually flying.

Combined across all its routes

78%
Arrive within 15 minutes
9 min
Average arrival delay
0.2%
Cancelled
3 min early
Median arrival delay

Based on 441 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon75%(64 flights)
  • Tue85%(58 flights)
  • Wed79%(62 flights)
  • Thu74%(62 flights)
  • Fri80%(65 flights)
  • Sat78%(63 flights)
  • Sun77%(65 flights)
On-time by departure window
  • 9 AM–12 PM—(2 flights)
  • 12–3 PM70%(10 flights)
  • 3–6 PM81%(94 flights)
  • 6–9 PM78%(333 flights)
On-time trend by month
68%
May

Jun 57% → May 68% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202557%30
July 202540%30
August 202558%31
September 202583%36
October 202581%62
November 202590%58
December 202584%32
January 202697%30
February 202679%28
March 202697%31
April 202693%30
May 202668%41
Departures on time
75%
Diverted
0.2%
Flights flown
439
Months covered
12

Keep nerding

Based on 441 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.