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Flight Reliability

UA 3621 · United Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and UA 3621 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

91%
Arrive within 15 minutes
8 min early
Average arrival delay
4.1%
Cancelled
14 min early
Median arrival delay

Based on 147 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon96%(24 flights)
  • Tue94%(17 flights)
  • Wed95%(19 flights)
  • Thu82%(22 flights)
  • Fri87%(23 flights)
  • Sat100%(16 flights)
  • Sun85%(20 flights)
On-time by departure window
  • 6–9 AM92%(98 flights)
  • 9 AM–12 PM88%(40 flights)
  • 12–3 PM—(3 flights)
On-time trend by month
95%
May

Jun 97% → May 95% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202597%30
July 202593%27
August 202586%14
January 202683%12
April 202693%29
May 202695%20
Departures on time
93%
Diverted
0%
Flights flown
141
Months covered
8

Keep nerding

Based on 147 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.