AS3121 San DiegoSAN · 18:33 DenverDEN · 22:12
AS3121 by Alaska Airlines flies from San Diego (SAN) to Denver (DEN).
scheduled from SAN
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 SAN and DEN are near their clear-air norm right now, so this reflects the route's recent baseline rather than a weather penalty. These figures come from both airports' records 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 →
Tomorrow at SAN
ForecastThu 12 Nov, local date
Forecast: GateWeather · incl. data from ECMWF (CC BY 4.0, modified) · Expected values for tomorrow from a forecast model, kept apart from today's measured figures.
Tomorrow at DEN
ForecastThu 12 Nov, local date
Forecast: GateWeather · incl. data from ECMWF (CC BY 4.0, modified) · Expected values for tomorrow from a forecast model, kept apart from today's measured figures.
When it flies
scheduled departuresEach mark is a scheduled departure at its origin-local time. Today is highlighted.
Other San Diego to Denver flights today
same route · Alaska AirlinesIf AS3121 is cancelled, these are the other Alaska Airlines nonstop flights from San Diego to Denver on the same day, with scheduled departure times in SAN local time. Most flights that show a delay still operate. Rebooking usually helps only when that delay is very large. Every airline on this route →
How AS3121 actually runs
Pro Flight Search has tracked every published board update for AS3121 across the SAN and DEN boards: schedule changes, gate pushes and actual clocks. Usually lands ~10 min early. Based on 4 confirmed landings · 3/4 within 15 min of schedule.
The verdict above is that record speaking, so it reflects how AS3121 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: N400SY, N407SY, N405SY.
Board clocks recorded as SAN and DEN published them.
Planning around AS3121? Will a delayed flight be cancelled? · Do planes make up time in the air? · How we measure
Journalists, bloggers, and researchers may cite this page with attribution and a link to Pro Flight Search.
Pro Flight Search: AS3121 San Diego to Denver on-time performance, measured from the SAN and DEN airport boards.
https://proflightsearch.com/flight/AS3121
.