MOUNT WASHINGTON, (AP) _ Three lightly clad hikers emerged safe today after 24 hours in snow, fog and wind on Mount Washington, where the wind-chill at the summit was 17 below zero this morning.

The three ignored advice from a shelter caretaker on the 6,288-foot mountain Sunday evening and continued toward the summit, said Peter Crane, a member of the staff at a mountaintop weather observatory.

A search official, Michael Torrey of the Appalachian Mountain Club, said the three - and a companion who turned back part way - probably set out from Pinkham Notch on the eastern side of the Northeast's tallest mountain at about 2 p.m. Sunday.

He said the hikers had no rain gear or warm clothes and were wearing blue jeans and poor boots. One had a sweatshirt, another a sweater and the third a parka. Their only provisions were two apples and a soda bottle full of water.

Maj. Henry Mock of the state Fish and Game Department said they reached Crawford Notch, a pass on the western side of the mountain, around 2 p.m. in good condition.

He identified them as Steve Sardella, 20, of Marlboro, Mass.; Matt Dube, 21, of Bethany, Conn.; and Andy Stewart, 23, of Syosset, New York. He said the man who turned back is Noel Bouvier of Boston.

Washington is notorious for severe and quickly changing weather.

''To survive in that kind of weather conditions, you have to be very well equipped,'' Mock said before the three were found.

Fish and game employees and volunteers helped search for the men, but weather conditions were too poor to send out planes, officials said.

Inexperienced hikers frequently get into trouble in the White Mountains because the weather changes quickly and is much harsher at higher elevations than at trailheads in valleys below.

The 6,288-foot mountain has some of the worst weather on Earth. Snow has fallen on the summit in every month, and numerous hikers have died after getting lost in blowing snow and fog in the past century.