Record-breaking heat will surge across the Southwest this week, impacting 70 million people. ☀️🌡️ Much of the Southwest is expected to shift from near-average temperatures to early summer heat this week, with highs climbing well into the 90s in many areas and topping 100 degrees Fahrenheit in some locations. These temperatures are more typical of early summer. The heat dome is expected to persist and may not begin to weaken until this weekend or early next week. All-time March record highs could be broken in some areas, and cities like Phoenix and Las Vegas could see their earliest 100-degree day on record. Across the mountains and deserts to the east, Las Vegas is forecast to reach 90 degrees or higher from Tuesday through next Monday. Records will be challenged through Saturday, and on some days, highs could exceed the previous records by 7-10 degrees. If Las Vegas reaches 100 on Friday, it would beat the city's earliest 100-degree temperature by several weeks. The current record fo...