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Flight Reliability

UA 4591 · United Airlines

Washington → Newark (DCA–EWR)95% of its flights flew this route. The rest (ORD–ICT, ORD–DSM) are included in these numbers.

78
Usually Fine
WanderNerd Reliability Score
80%
Arrive within 15 minutes
7 min
Average arrival delay
2.6%
Cancelled
9 min early
Median arrival delay

Based on 307 historical flights. Data through May 2026.

What the data says

Morning flights do better here.

UA 4591 departing between 9 AM–12 PM arrived on time 80% of the time, versus 73% between 3–6 PM.

Monday is the weak spot.

UA 4591 arrived on time 89% of the time on Saturdays. On Mondays: 75%.

Better than the DCA–EWR route average.

UA 4591 arrived on time 80% of the time, versus 71% across the DCA–EWR route.

Slipping a little lately.

UA 4591 arrived on time 84% of the time over the last three months in the data, compared with 87% in the three months before that.

The breakdown

On-time by weekday
  • Mon75%(44 flights)
  • Tue78%(46 flights)
  • Wed86%(44 flights)
  • Thu83%(46 flights)
  • Fri77%(47 flights)
  • Sat89%(26 flights)
  • Sun76%(46 flights)
On-time by departure window
  • 6–9 AM—(1 flights)
  • 9 AM–12 PM80%(283 flights)
  • 12–3 PM—(4 flights)
  • 3–6 PM73%(11 flights)
On-time trend by month
86%
May

Jul 74% → May 86% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
July 202574%27
August 202581%26
September 202573%26
October 202565%26
November 202567%27
December 202582%22
January 202689%26
February 202692%25
March 202684%31
April 202683%30
May 202686%28
Departures on time
86%
Diverted
0%
Flights flown
299
Months covered
12

Same route, other flights

Keep nerding

Based on 307 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.