WN4251 BostonBOS · 17:00 DenverDEN · 19:35
WN4251 by Southwest Airlines flies from Boston (BOS) to Denver (DEN) for the Tue, Sep 22 departure.
en route from BOS to DEN
board checked 39m ago · checking again in 45s
Board estimate · gate and arrival times. Off blocks 19:40 · typical taxi-out at BOS ≈ 9.8 min. No receiver coverage over open ocean.
Where the minutes go
last 4 operations · gate push → arrivalThe bar is how late it left the gate; the ring is where it actually arrived. Board clocks, not estimates.
The route today
live boardsWeather lens
Delay & cancellation outlook for this flight
Measured, 90-day sampleConditions at BOS and DEN are near their clear-air norm right now, so this reflects the route's recent baseline rather than a weather penalty. For this route and airline, under conditions like today's, over the last 90 days.
Pro Flight Search tracking, 90 days · the weather × delay correlation study → · live weather risk by airport →
When it flies
scheduled departuresEach mark is a scheduled departure at its origin-local time. Today is highlighted.
Other Boston to Denver flights today
same route · Southwest AirlinesIf WN4251 is cancelled, these are the other Southwest Airlines nonstop flights from Boston to Denver on the same day, with scheduled departure times in BOS local time. Most flights posting a delay still operate — rebooking usually only beats a very large posted delay. Every airline on this route →
How WN4251 actually runs
Pro Flight Search has tracked every published board update for WN4251 across the BOS and DEN boards: schedule changes, gate pushes and actual clocks. Usually lands ~150 min late. Based on 3 confirmed landings · 0/3 within 15 min of schedule. Pushes back late but makes up time in the air.
The verdict above is that record speaking, so it reflects how WN4251 operates rather than what the timetable promises. Numbers refresh as new flights operate.
How this operation is measured
Board log
scheduled → actual, per operationAircraft
Recent tails: N8910Q, N9001F, N8854Q.
Board clocks recorded as BOS and DEN published them.
Planning around WN4251? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
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Pro Flight Search — WN4251 Boston to Denver on-time performance, measured from the BOS and DEN airport boards.
https://proflightsearch.com/flight/WN4251
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