The contiguous United States had its hottest summer on record in 2026, with an average temperature of 74.4°F (23.6°C) from June to August, according to the National Oceanic and Atmospheric Administration (NOAA). This beats the previous records set in 1936 and 2021 by 0.4°F. August 2026 alone was the warmest month ever recorded in the U.S., with an average temperature of 75.6°F (24.2°C). The average daytime high for August was 88.6°F, the highest of its kind on record. In recent years, the U.S. has seen a surge in extreme heat. Four of the hottest summers on record have occurred within the past five years, with 2022 and 2024 taking fourth and fifth places, respectively. Scientists say this trend is largely due to human-caused climate change, driven by the burning of fossil fuels, which increases greenhouse gases in the atmosphere and traps more heat. Most states saw temperatures that were above or much above average for August, with only parts of the northern Plains and Midwest experiencing near-average conditions. Precipitation levels were below average, placing the U.S. in the driest third of historical records for both August and the summer as a whole. By September 1, nearly 60% of the contiguous U.S. was under drought conditions. Notably, Lake Mead, the largest reservoir in the U.S., reached its lowest level on record, dropping 1.5 feet (0.5 meters) below its previous low in July 2022. While much of the country faced extreme heat and dryness, some areas experienced heavy rainfall. In central Indiana, 11 inches (28 centimeters) of rain fell between August 11 and 17, brought by severe storms. Alaska and Hawaii also saw unusually warm conditions, with August temperatures ranking in the warmest third of historical records. Hawaii, in particular, experienced its third-warmest August and its second-wettest on record due to Hurricane Lala. Meanwhile, in the southwestern U.S., including California, Nevada, New Mexico, and Colorado, August temperatures were the warmest on record, with even nighttime lows hitting record highs. Nationwide, the total rainfall from June to August was below average, contributing to the ongoing drought conditions.