- Average temperature, summer 2024: 89.9°F (+4.7°F above normal)
- Average maximum, summer 2024: 103.5°F (+4.2°F above normal)
- Average minimum, summer 2024: 76.2°F (+5.1°F above normal)
- Prior record: summer 2011 (90.5°F)
- County seat: Florence
To determine the counties that just had their hottest temperatures on record, 24/7 Wall St. reviewed county-level data on average monthly temperatures from the NOAA’s National Centers for Environmental Information. All counties in the contiguous U.S. were ranked based on the difference in average daily temperature in summer 2024 (June through August) from historical summer averages from 1901 to 2000. Only counties where summer 2024 ranks as the hottest summer on record – going back to 1895 – were included.