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WanderNerd

Flight Reliability

UA 4578 · United Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and UA 4578 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

80%
Arrive within 15 minutes
2 min
Average arrival delay
2.7%
Cancelled
11 min early
Median arrival delay

Based on 255 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon75%(40 flights)
  • Tue84%(31 flights)
  • Wed80%(39 flights)
  • Thu83%(36 flights)
  • Fri76%(49 flights)
  • Sat100%(22 flights)
  • Sun73%(30 flights)
On-time by departure window
  • 6–9 AM82%(33 flights)
  • 9 AM–12 PM80%(163 flights)
  • 12–3 PM67%(15 flights)
  • 6–9 PM86%(36 flights)
On-time trend by month
76%
May

Jul 65% → May 76% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
July 202565%23
August 202591%22
September 202590%29
October 202586%22
December 202579%29
January 202684%19
February 202668%19
March 202674%23
April 202689%28
May 202676%25
Departures on time
82%
Diverted
0.4%
Flights flown
247
Months covered
12

Based on 255 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.