A prolonged and unusual March heat wave is gripping cities across the West

SAN FRANCISCO (AP) — San Franciscans bared an unusual amount of skin for this time of year Tuesday, as a city better known for its chilly summers, drizzle and fog experienced its hottest March in at least two decades, part of a rare winter heat wave baking the U.S. West.

While the Bay Area flirts with nearly 90 degree (32.2 C) highs, Phoenix is expected to top 100 F (37.7 C) this week — something it usually does in early May and has never done before March 26. Las Vegas could see its hottest March stretch ever recorded.