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Flight Reliability

UA 1637 · United Airlines

Phoenix → Denver (PHX–DEN)87% of its flights flew this route. The rest (ORD–MSP, MSP–EWR) are included in these numbers.

79
Usually Fine
WanderNerd Reliability Score
75%
Arrive within 15 minutes
12 min
Average arrival delay
0.6%
Cancelled
5 min early
Median arrival delay

Based on 319 historical flights. Data through May 2026.

What the data says

The 3–6 PM departure wins.

UA 1637 departing between 3–6 PM arrived on time 83% of the time, versus 71% between 6–9 PM.

Sunday scaries are real for this one.

UA 1637 arrived on time 80% of the time on Fridays. On Sundays: 71%.

A bit behind the United Airlines network.

UA 1637 arrived on time 75% of the time, versus 79% across the United Airlines network.

Slipping a little lately.

UA 1637 arrived on time 78% of the time over the last three months in the data, compared with 83% in the three months before that.

The breakdown

On-time by weekday
  • Mon74%(50 flights)
  • Tue78%(32 flights)
  • Wed72%(50 flights)
  • Thu80%(50 flights)
  • Fri80%(51 flights)
  • Sat72%(32 flights)
  • Sun71%(51 flights)
On-time by departure window
  • 6–9 AM—(3 flights)
  • 9 AM–12 PM—(8 flights)
  • 3–6 PM83%(96 flights)
  • 6–9 PM71%(209 flights)
On-time trend by month
91%
May

Jun 71% → May 91% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202571%28
July 202562%29
August 202576%25
September 202574%23
October 202582%28
November 202550%24
December 202584%31
January 202684%31
February 202682%28
March 202673%26
April 202671%21
May 202691%22
Departures on time
78%
Diverted
0.3%
Flights flown
316
Months covered
12

Same route, other flights

Keep nerding

Based on 319 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.