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Flight Reliability

UA 4251 · United Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and UA 4251 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

83%
Arrive within 15 minutes
7 min
Average arrival delay
2.3%
Cancelled
10 min early
Median arrival delay

Based on 346 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon84%(49 flights)
  • Tue87%(46 flights)
  • Wed87%(45 flights)
  • Thu81%(48 flights)
  • Fri79%(52 flights)
  • Sat85%(47 flights)
  • Sun78%(51 flights)
On-time by departure window
  • 6–9 AM92%(141 flights)
  • 9 AM–12 PM83%(24 flights)
  • 12–3 PM—(2 flights)
  • 3–6 PM71%(101 flights)
  • 6–9 PM81%(52 flights)
  • 9 PM–12 AM83%(18 flights)
On-time trend by month
75%
May

Jun 74% → May 75% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202574%27
July 202597%30
August 2025100%27
September 202591%22
October 202594%31
November 202579%29
December 202580%30
January 202672%29
February 202681%26
March 202680%30
April 202672%29
May 202675%28
Departures on time
83%
Diverted
0%
Flights flown
338
Months covered
12

Keep nerding

Based on 346 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.