(UA) United Airlines 4638 On-Time Performance Rating

Date Range:

15-Jan-2026 to 15-Mar-2026

(BOI) Boise Air Terminal

Boise, ID, US

(SFO) San Francisco International Airport

San Francisco, CA, US

On-Time Performance Chart

(using rounded numbers)

On-Time

100%

Late

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.)

Standard Deviation

Min

Max

UA 4638 On-Time Performance Details

Overall Rating

3.1 of 5

Average

Percentage On-Time 100%

Average Delay Time 0 min

FlightStats Rating is a merit measurement considering both on-time performance and delay severity. The score, 3.1 shows that this flight has on-time performance characteristics better than 60% of all other flights in the FlightStats database.

On-Time Performance Rating

3.6 of 5

Good

Percentage On-Time 100%

This flight has an on-time performance of 100%. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight is on-time more often than 73% of other flights.

Delay Performance

2.5 of 5

Average

Average Delay Time 0 min

This flight has an average delay of 0 minutes with a standard deviation of 0 minutes. Statistically, when taking into consideration sample size, standard deviation, and mean, this flight has delay performance characteristics better than 50% of other flights.