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
19:23 MDT
Timezone
America/Denver
Type
Large Airport
Elevation
5,431 ft
Coordinates
39.8600, -104.6738

cloud Weather

Wind
230° / 8 kt
Visibility
10 SM
Ceiling
BKN 9,000 ft, BKN 13,000 ft, BKN 22,000 ft
Temp / Dew
28°C / 8°C
Altimeter
30.14 inHg

Obs: 2026-08-29T00:53:00.000Z

Raw METAR / TAF 
METAR KDEN 290053Z 23008KT 10SM BKN090 BKN130 BKN220 28/08 A3014 RMK AO2 WSHFT 2348 VIRGA W-NW SLP121 T02830078

TAF KDEN 290055Z 2901/3006 25010KT P6SM BKN100 BKN140 PROB30 2901/2902 VRB15G30KT -SHRA BKN100 FM290200 24010KT P6SM SCT120 BKN200 FM290500 21009KT P6SM SCT120 SCT200 FM291600 25007KT P6SM FEW110 SCT200 FM291900 25010KT P6SM VCSH SCT100 BKN150 TEMPO 2920/2924 VRB20G35KT -TSRA BKN080CB FM300000 33012KT P6SM SCT100 BKN150 PROB30 3000/3004 -SHRA BKN100

flight Live Traffic

flight_takeoff 306 Departures
flight_land 481 Arrivals

Arrival

SEA KSEA VFR

Seattle–Tacoma International Airport

Seattle, US

Local time
18:23 PDT
Timezone
America/Los_Angeles
Type
Large Airport
Elevation
433 ft
Coordinates
47.4479, -122.3103

cloud Weather

Wind
210° / 4 kt
Visibility
10 SM
Ceiling
FEW 3,500 ft, BKN 6,000 ft
Temp / Dew
21°C / 11°C
Altimeter
29.99 inHg

Obs: 2026-08-29T00:53:00.000Z

Raw METAR / TAF 
METAR KSEA 290053Z 21004KT 10SM FEW035 BKN060 21/11 A2999 RMK AO2 SLP160 T02110106 $

TAF KSEA 282322Z 2900/3006 23009KT P6SM SCT025 BKN050 FM290200 32006KT P6SM BKN050 FM290800 19007KT P6SM -SHRA OVC030 FM291100 19006KT P6SM -SHRA BKN025 OVC030 FM291800 21007KT P6SM -SHRA SCT020 OVC030 FM292000 23008KT P6SM -SHRA SCT025 BKN040

flight Live Traffic

flight_takeoff 193 Departures
flight_land 194 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.