It is a hot, sunny afternoon and the day started calm. Which way does a sea breeze blow at the coast?
A coast seen side-on on a sunny day: cool sea on the left, hot land on the right with heat rising from it. A two-headed arrow with a question mark lies along the surface between sea and land.
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From the sea on to the land. The land heats up faster than the sea. Warm air rises over the land and cooler air is drawn in from the sea to replace it, giving an onshore breeze that builds through the afternoon. At night the flow can reverse as a land breeze.
