A powerful heat dome is causing record-breaking March heat across the western U.S., with temperatures soaring 15–30°F above normal and even crossing 100°F in desert regions. This extreme warmth is expanding eastward, bringing widespread 80s and 90s to central states. This early-season heat raises serious health risks, accelerates rapid snowmelt in mountains, increases wildfire danger, and dries vegetation. Major cities like Phoenix, Las Vegas, and Los Angeles are already seeing historic highs, with more records expected.