Coastal describes anything related to the coast, the place where land meets the ocean or sea. A coastal town sits near the shore, where residents might hear waves crashing and smell salt air. Coastal waters are the parts of the ocean close to land, where the water is typically shallower than in the open sea.

The word helps distinguish between places and things near the ocean versus those far inland. California and Maine are coastal states because they border the ocean, while Kansas and Colorado are landlocked. Coastal areas often have different weather than inland regions: they tend to be milder because the ocean moderates temperature, staying cooler in summer and warmer in winter.

People sometimes talk about coastal communities or coastal life to describe the culture and lifestyle of places where the ocean shapes daily experience. Fishing, shipping, and tourism are often important to coastal economies. Scientists study coastal ecosystems where saltwater and freshwater mix, creating unique habitats for creatures like crabs, herons, and sea turtles.