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Flight Reliability

UA 4421 · United Airlines

SGF → Chicago (SGF–ORD)84% of its flights flew this route. The rest (IAD–SYR, EWR–BTV) are included in these numbers.

69
Usually Fine
WanderNerd Reliability Score
80%
Arrive within 15 minutes
17 min
Average arrival delay
3.6%
Cancelled
9 min early
Median arrival delay

Based on 363 historical flights. Data through May 2026.

What the data says

Sunday comes out ahead.

A small edge: 83% on time on Sundays against 77% on Thursdays.

Better than the SGF–ORD route average.

UA 4421 arrived on time 80% of the time, versus 70% across the SGF–ORD route.

Keep a backup plan handy.

UA 4421 was cancelled 3.6% of the time. Typical for U.S. flights is around 1–2%.

Slipping a little lately.

UA 4421 arrived on time 71% of the time over the last three months in the data, compared with 78% in the three months before that.

The breakdown

On-time by weekday
  • Mon81%(48 flights)
  • Tue82%(51 flights)
  • Wed78%(50 flights)
  • Thu77%(52 flights)
  • Fri78%(51 flights)
  • Sat82%(49 flights)
  • Sun83%(48 flights)
On-time by departure window
  • 6–9 AM80%(312 flights)
  • 12–3 PM80%(35 flights)
  • 3–6 PM—(2 flights)
On-time trend by month
73%
May

Jun 93% → May 73% on time

On-time arrival percentage by month
MonthOn-time percentageFlights
June 202593%30
July 202590%31
August 202580%30
September 202583%30
October 202584%31
November 202582%28
December 202572%29
January 202668%28
February 202693%28
March 202679%28
April 202662%26
May 202673%30
Departures on time
85%
Diverted
0.3%
Flights flown
349
Months covered
12

Same route, other flights

Keep nerding

Based on 363 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.