noun
mountain-valley winds; mountain and valley breeze
A meteorological term referring to local wind systems that blow upslope during the day (valley breeze) and downslope at night (mountain breeze).
山谷風は、日中は谷から山へ、夜間は山から谷へ吹く風のことです。
Mountain-valley winds are winds that blow from the valley to the mountain during the day and from the mountain to the valley at night.