(UA) United Airlines 3991 On-Time Performance Rating

Date Range:

15-Nov-2025 to 15-Jan-2026

(BHM) Birmingham-Shuttlesworth International Airport

Birmingham, AL, US

(IAH) Houston George Bush Intercontinental Airport

Houston, TX, US

On-Time Performance Chart

(using rounded numbers)

On-Time

71%

Late

14%

Very Late

Excessive

Cancelled

Diverted

Delay Statistics

(Aggregate Arrival Delay Statistics for this Flight)

Total Flights Observed

Total Delays ( > 1 min )

Codeshares

Average Delay (min.)

29.4

Standard Deviation

16.8

Min

Max

UA 3991 On-Time Performance Details

Overall Rating

2.6 of 5

Average

Percentage On-Time 71%

Average Delay Time 29.4 min

FlightStats Rating is a merit measurement considering both on-time performance and delay severity. The score, 2.6 shows that this flight has on-time performance characteristics better than 51% of all other flights in the FlightStats database.

On-Time Performance Rating

2.1 of 5

Average

Percentage On-Time 71%

This flight has an on-time performance of 71%. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight is on-time more often than 42% of other flights.

Delay Performance

3.1 of 5

Average

Average Delay Time 29.4 min

This flight has an average delay of 29.4 minutes with a standard deviation of 16.8 minutes. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight has delay performance characteristics better than 62% of other flights.