Skip to content
WanderNerd
Check a flight

Flight Reliability

UA 4309 · United Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and UA 4309 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
15 min
Average arrival delay
2.7%
Cancelled
9 min early
Median arrival delay

Based on 330 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon83%(46 flights)
  • Tue89%(44 flights)
  • Wed86%(42 flights)
  • Thu85%(46 flights)
  • Fri87%(46 flights)
  • Sat80%(50 flights)
  • Sun72%(46 flights)
On-time by departure window
  • 6–9 AM80%(25 flights)
  • 9 AM–12 PM—(3 flights)
  • 12–3 PM—(3 flights)
  • 3–6 PM88%(111 flights)
  • 6–9 PM80%(178 flights)
On-time trend by month
90%
May

Jun 59% → May 90% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202559%27
July 202552%25
August 202584%31
September 202593%30
October 202575%28
November 202586%21
December 202587%30
January 202690%30
February 202696%27
March 2026100%11
April 202687%30
May 202690%30
Departures on time
82%
Diverted
0.3%
Flights flown
320
Months covered
12

Keep nerding

Based on 330 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.