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Flight Reliability

UA 1399 · United Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and UA 1399 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

79%
Arrive within 15 minutes
6 min
Average arrival delay
1.6%
Cancelled
8 min early
Median arrival delay

Based on 387 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon82%(60 flights)
  • Tue88%(43 flights)
  • Wed71%(44 flights)
  • Thu81%(57 flights)
  • Fri79%(58 flights)
  • Sat79%(58 flights)
  • Sun73%(60 flights)
On-time by departure window
  • 3–6 AM92%(38 flights)
  • 6–9 AM84%(106 flights)
  • 9 AM–12 PM91%(22 flights)
  • 3–6 PM76%(42 flights)
  • 6–9 PM73%(138 flights)
  • 9 PM–12 AM71%(34 flights)
On-time trend by month
88%
May

Jun 57% → May 88% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202557%30
July 202590%20
August 202589%26
September 202568%22
October 202572%32
November 202575%51
December 202588%32
January 202673%30
February 202696%27
March 202667%30
April 202687%30
May 202688%50
Departures on time
82%
Diverted
0.3%
Flights flown
380
Months covered
12

Keep nerding

Based on 387 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.