Apparatus

Try JFK, AAL1290, BAW, or N225AN.

flight_takeoff Flight

UAL3940

Operated by United Airlines

Live map

Live map filtered to UAL3940. Shown when the flight is currently airborne.

Route airports View route page →

Departure

DEN KDEN VFR

Denver International Airport

Denver, US

Local time
21:56 MDT
Timezone
America/Denver
Type
Large Airport
Elevation
5,431 ft
Coordinates
39.8600, -104.6738

cloud Weather

Wind
210° / 21G30 kt
Visibility
10 SM
Ceiling
FEW 12,000 ft
Temp / Dew
21°C / 1°C
Altimeter
29.83 inHg

Obs: 2026-10-13T02:53:00.000Z

Raw METAR / TAF 
METAR KDEN 130253Z 21021G30KT 10SM FEW120 21/01 A2983 RMK AO2 PK WND 20037/0227 SLP024 T02110011 53009

TAF KDEN 130254Z 1303/1406 21021G30KT P6SM FEW120 FM130400 30010G22KT P6SM FEW100 FM130700 34010KT P6SM FEW020 SCT040 FM131100 01006KT P6SM BKN010 BKN030 TEMPO 1312/1315 5SM BR BKN005 FM131700 04007KT P6SM SCT020 BKN040 FM132000 07010G20KT P6SM FEW040 SCT100 FM140200 05009KT P6SM VCSH SCT050

flight Live Traffic

flight_takeoff 443 Departures
flight_land 352 Arrivals

Arrival

SEA KSEA VFR

Seattle–Tacoma International Airport

Seattle, US

Local time
20:56 PDT
Timezone
America/Los_Angeles
Type
Large Airport
Elevation
433 ft
Coordinates
47.4479, -122.3103

cloud Weather

Wind
0° / 0 kt
Visibility
10 SM
Ceiling
FEW 17,000 ft, SCT 23,000 ft
Temp / Dew
13°C / 2°C
Altimeter
30.07 inHg

Obs: 2026-10-13T02:53:00.000Z

Raw METAR / TAF 
METAR KSEA 130253Z 00000KT 10SM FEW170 SCT230 13/02 A3007 RMK AO2 SLP190 T01280022 53007

TAF KSEA 130259Z 1303/1406 VRB03KT P6SM SCT250 FM130900 16004KT P6SM OVC100 FM131800 20005KT P6SM OVC100 FM132300 23005KT P6SM OVC050 FM140400 19004KT P6SM SCT025 OVC040

flight Live Traffic

flight_takeoff 217 Departures
flight_land 264 Arrivals

Recent history last 30

DateAircraftRouteTakeoffLandingDurationDep ΔArr Δ
2026-07-21 A0B886 DEN → SEA Jul 21, 13:18 UTCJul 21, 13:59 UTC41m +48m +7m
2026-07-21 A0B886 DEN → SEA Jul 21, 13:10 UTCJul 21, 14:05 UTC55m - -
2026-07-18 AA6B9D DEN → SEA Jul 18, 19:00 UTCJul 18, 21:35 UTC2h 35m - -
2026-07-15 AC2706 - Jul 15, 12:25 UTCJul 15, 16:25 UTC4h 0m - -
2026-07-11 A609D4 IAD → ATL Jul 11, 12:40 UTCJul 11, 13:55 UTC1h 15m - -
2026-07-07 A8F00E - Jul 7, 17:40 UTCJul 8, 00:40 UTC7h 0m - -
2026-07-07 A8F00E LHR → EWR Jul 7, 17:40 UTCJul 8, 00:40 UTC7h 0m +400m +5m
2026-07-04 A7F4E7 - Jul 4, 18:20 UTCJul 4, 21:00 UTC2h 40m - -
2026-07-04 A7F4E7 LHR → SFO Jul 4, 18:25 UTCJul 5, 04:55 UTC10h 30m +25m +9m
2026-07-04 A7F4E7 LHR → SFO Jul 4, 18:25 UTCJul 5, 04:50 UTC10h 25m +25m +4m
2026-07-03 A31A7B ORD → GIG Jul 3, 11:33 UTCJul 3, 20:52 UTC9h 19m +573m -33m
2026-07-03 A31A7B - Jul 3, 11:10 UTCJul 3, 20:50 UTC9h 40m - -
2026-07-01 A31A7B ORD → GIG Jul 1, 05:29 UTCJul 1, 07:20 UTC1h 51m +179m +13m
2026-07-01 A31A7B - Jul 1, 05:10 UTCJul 1, 07:20 UTC2h 10m - -
2026-06-27 AB8CC1 DCA → ORD Jun 27, 15:05 UTCJun 27, 16:55 UTC1h 50m - -
2026-06-27 AB8CC1 DCA → ORD Jun 27, 15:15 UTCJun 27, 16:40 UTC1h 25m +15m +21m
2026-06-25 AA4440 - Jun 25, 00:35 UTCJun 25, 09:40 UTC9h 5m - -
2026-06-24 AA4440 GRU → EWR Jun 24, 23:22 UTCJun 25, 09:40 UTC10h 18m +22m +2m
2026-06-21 A6ED7F DEN → SEA Jun 21, 11:55 UTCJun 21, 13:54 UTC2h 0m - -
2026-06-21 A6ED7F DEN → SEA Jun 21, 11:46 UTCJun 21, 13:51 UTC2h 5m +16m +6m
2026-06-19 AC033E DEN → SEA Jun 19, 12:25 UTCJun 19, 13:14 UTC50m - -
2026-06-16 AA4C1A DEN → SEA Jun 16, 18:52 UTCJun 16, 19:34 UTC42m +112m +11m
2026-06-16 AA4C1A DEN → SEA Jun 16, 18:50 UTCJun 16, 19:15 UTC25m - -
2026-06-15 A126EC DEN → SEA Jun 15, 06:30 UTCJun 15, 06:49 UTC20m - -
2026-06-15 A126EC DEN → SEA Jun 15, 06:03 UTCJun 15, 13:45 UTC7h 42m +288m -8m
2026-06-12 AB9B9D DEN → SEA Jun 12, 10:30 UTCJun 12, 12:10 UTC1h 40m - -
2026-06-12 AB9B9D DEN → SEA Jun 12, 10:27 UTCJun 12, 12:10 UTC1h 43m +27m -3m
2026-06-10 A5F581 DEN → SEA Jun 10, 04:49 UTCJun 10, 06:45 UTC1h 56m +19m -23m
2026-06-10 A5F581 DEN → SEA Jun 10, 04:50 UTCJun 10, 06:45 UTC1h 55m - -
2026-06-06 A254D8 DEN → SEA Jun 6, 11:25 UTCJun 6, 13:25 UTC2h 0m - -

Performance history

Flights tracked
48 showing last 30
Avg arrival delay
+1m
On-time arrival
92% 92% on time
Aircraft used
16

Monthly activity 4 months

Month Flights tracked
July 2026 14
June 2026 17
May 2026 12
April 2026 5

UAL3940 frequently asked

Where does flight UAL3940 fly?
UAL3940 (United Airlines) flies from DEN to SEA. View the full route page.
How long is flight UAL3940?
Based on observed flights, UAL3940 takes on average 3h 52m from takeoff to landing.
How often does UAL3940 fly?
UAL3940 has been observed flying several times a week in our tracking data. We've recorded 48 flights under this callsign.
Is flight UAL3940 usually on time?
Across recent flights, UAL3940 arrives with an average 1-minute delay. 92% of flights arrive within 15 minutes of schedule.
What aircraft operates flight UAL3940?
UAL3940 has been operated by 16 different aircraft in our records. Tail numbers are listed in the recent history below.
Can I track UAL3940 live?
Yes. When UAL3940 is currently airborne, the live tracker map above shows its real-time position from ADS-B broadcasts. If the map is empty, the flight is not currently in the air.