Condensation from the fogs also produces fog drip from trees overnight.

Rainfall is heavy during the winter and summers are almost completely dry with the exception of fog drip caused by the fog passing through the trees.

Most precipitation occurs as rain, but also includes snow, hail, fog drip, graupel, and sleet.

"If fog drip contributes to stream flows, that would be a real plus for these animals," he said.

Cool coastal air and fog drip keep this forest consistently damp year round.

The effective moisture, of course, is much greater because of fog drip.

He found redwoods are extremely efficient producers of fog drip.

During summer, fog drip is a primary source of moisture for plants that would otherwise not be able to persist with such low summer precipitation.

Most of the precipation occurs in winter but summer fogs moisture is extracted by the trees and produces a fog drip keeping the forest moist.

Dawson reported that in a study of northern California redwood forests, 34% of annual hydrologic input was from fog drip.