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Flight Reliability

UA 3998 · United Airlines

This number covered several routes in this period.

One number, several routes.

Airlines reuse flight numbers, and UA 3998 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
7 min
Average arrival delay
3.2%
Cancelled
11 min early
Median arrival delay

Based on 222 historical flights. Data through May 2026.

The breakdown

On-time by weekday
  • Mon91%(32 flights)
  • Tue86%(29 flights)
  • Wed83%(29 flights)
  • Thu78%(32 flights)
  • Fri82%(27 flights)
  • Sat79%(34 flights)
  • Sun84%(31 flights)
On-time by departure window
  • 3–6 AM71%(21 flights)
  • 6–9 AM100%(14 flights)
  • 9 AM–12 PM92%(26 flights)
  • 12–3 PM—(9 flights)
  • 3–6 PM71%(55 flights)
  • 6–9 PM89%(89 flights)
On-time trend by month
74%
May

Oct 85% → May 74% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
October 202585%26
November 202582%27
December 202597%29
January 202693%29
February 202686%28
March 202657%28
April 2026100%10
May 202674%31
Departures on time
85%
Diverted
0.5%
Flights flown
214
Months covered
9

Keep nerding

Based on 222 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.