A significant heat dome has settled over the United States, resulting in unprecedented March heat records in 14 states and sparking concerns about a potentially historic heat wave. This phenomenon, characterized by a high-pressure system that traps warm air, has already brought record-breaking temperatures to the Southwest, with Flagstaff, Arizona, experiencing 11 to 12 consecutive days of extreme heat. Meteorologist Gregg Gallina from the National Weather Service anticipates the heat dome will spread eastward, pushing temperatures into the 90s°F (mid-30s°C) across the southern and central Plains by Wednesday. This means that one-quarter to one-third of the continental U.S. is nearing record temperatures for March. Climatologist Maximiliano Herrera notes that states like California, Arizona, and Nevada have already recorded their hottest March days ever.