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Flight Reliability

UA 1639 · United Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and UA 1639 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

71%
Arrive within 15 minutes
21 min
Average arrival delay
2.3%
Cancelled
2 min
Median arrival delay

Based on 434 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon68%(62 flights)
  • Tue79%(53 flights)
  • Wed75%(48 flights)
  • Thu70%(70 flights)
  • Fri64%(69 flights)
  • Sat72%(57 flights)
  • Sun71%(63 flights)
On-time by departure window
  • 6–9 AM84%(142 flights)
  • 9 AM–12 PM62%(21 flights)
  • 12–3 PM58%(81 flights)
  • 3–6 PM57%(62 flights)
  • 6–9 PM62%(69 flights)
  • 9 PM–12 AM89%(47 flights)
On-time trend by month
71%
May

Jun 48% → May 71% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202548%29
July 202557%85
August 202579%47
September 202590%30
October 202594%31
November 202590%29
December 202574%27
January 202675%16
February 202643%14
March 202643%21
April 202687%31
May 202671%62
Departures on time
76%
Diverted
0.5%
Flights flown
422
Months covered
12

Keep nerding

Based on 434 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.