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Flight Reliability

UA 5821 · United Airlines

Chicago → Milwaukee (ORD–MKE)84% of its flights flew this route. The rest (TUL–DEN, SFO–OMA) are included in these numbers.

64
A Little Dicey
WanderNerd Reliability Score
73%
Arrive within 15 minutes
9 min
Average arrival delay
3.1%
Cancelled
7 min early
Median arrival delay

Based on 360 historical flights. Data through May 2026.

What the data says

Morning-you made the right choice.

UA 5821 departing between 6–9 AM arrived on time 82% of the time, versus 58% between 3–6 PM.

Skip Monday if you can.

UA 5821 arrived on time 80% of the time on Tuesdays. On Mondays: 65%.

Better than the ORD–MKE route average.

UA 5821 arrived on time 73% of the time, versus 64% across the ORD–MKE route.

A bit behind the United Airlines network.

UA 5821 arrived on time 73% of the time, versus 79% across the United Airlines network.

The breakdown

On-time by weekday
  • Mon65%(49 flights)
  • Tue80%(50 flights)
  • Wed74%(49 flights)
  • Thu77%(51 flights)
  • Fri67%(49 flights)
  • Sat79%(48 flights)
  • Sun71%(49 flights)
On-time by departure window
  • 6–9 AM82%(72 flights)
  • 9 AM–12 PM73%(247 flights)
  • 3–6 PM58%(26 flights)
On-time trend by month
83%
May

Jun 87% → May 83% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202587%30
July 202580%30
August 202582%28
September 202583%29
October 202570%30
November 202565%26
December 202558%31
January 202659%29
February 202667%27
March 202673%26
April 202672%29
May 202683%30
Departures on time
75%
Diverted
1.1%
Flights flown
345
Months covered
12

Same route, other flights

Keep nerding

Based on 360 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.