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United Airlines

Is UA4639 delayed?

Service date: · Scheduled arrival date; departure time unavailable (America/Los_Angeles)

Arrived

17 min late

Official source · Updated

Departure

Boise

BOI

Scheduled

Not available

Arrival

San Francisco

SFO

Actual

Scheduled 09:18

Sep 7

Times shown in airport local time

Flight details

Departure · UTC

Scheduled
Not available
Estimated
Not available
Actual
Not available

Arrival · UTC

Scheduled
Estimated
Actual

Recent arrivals

Dates below are arrival dates in the destination airport’s time zone. The detailed history uses service dates.

  • BOI → SFO

    13 min late

  • BOI → SFO

    43 min late

  • BOI → SFO

    43 min late

  • BOI → SFO

    62 min late

  • BOI → SFO

    30 min late
Flight history and details

Aug 23, 2026 — Sep 22, 2026

Observed arrivals
18
Arrivals over 15 minutes late
8
Observed cancellations
0
Observed occurrences
18

Results compare scheduled and actual arrival times. Cancelled or diverted flights are excluded. Some flights may be missing from the history.

How flight status works

UA4639 Recent arrival history
Service dateDepartureArrivalActualArrival delay (minutes)
Sep 21, 2026ArrivedBoiseSan Francisco
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13
Sep 20, 2026ArrivedBoiseSan Francisco
43
Sep 19, 2026ArrivedBoiseSan Francisco
43
Sep 18, 2026ArrivedBoiseSan Francisco
62
Sep 17, 2026ArrivedBoiseSan Francisco
30
Sep 16, 2026ArrivedBoiseSan Francisco
20
Sep 15, 2026ArrivedBoiseSan Francisco
-14
Sep 14, 2026ArrivedBoiseSan Francisco
-19
Sep 13, 2026ArrivedBoiseSan Francisco
-15
Sep 12, 2026ArrivedBoiseSan Francisco
-13
Sep 11, 2026ArrivedBoiseSan Francisco
44
Sep 10, 2026ArrivedBoiseSan Francisco
-18
Sep 9, 2026ArrivedBoiseSan Francisco
13
Sep 8, 2026ArrivedBoiseSan Francisco
-18
Sep 7, 2026ArrivedBoiseSan Francisco
17
Sep 6, 2026ArrivedBoiseSan Francisco
6
Sep 5, 2026ArrivedBoiseSan Francisco
50
Sep 4, 2026ArrivedBoiseSan Francisco
-10

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