The contiguous United States sizzled to its hottest month ever last month, according to the National Oceanic and Atmospheric Administration. July averaged 76.89 degrees Fahrenheit (24.94 degrees Celsius) across the Lower 48 states, eclipsing the Dust Bowl’s July 1936 by an eighth of a degree. The biggest driver of the record heat was nighttime lows that smashed the old mark for hottest minimums by 0.7 degrees, NOAA said. “If you’re talking heat waves, that nighttime low is incredibly important for determining total heat stress,” Masters said. Because of climate change, Masters said, “this may be one of the coolest years we’re gonna experience for the rest of our lives.”