PHOENIX (AP) — The Latest on extreme heat in the Southwest (all times local):

1:30 p.m.

Extremely hot and dry conditions in Southern California deserts have forced Joshua Tree National Park to close the popular 49 Palms Oasis hiking area.

The park says water sources are dwindling and desert bighorn sheep will not come down to the oasis to drink if visitors are in the area.

Hikers will be allowed only a half-mile down the trail before reaching the closure point.

The oasis is in a rocky canyon, where towering fan palms shade clear pools of water.