July was the hottest month ever recorded in the United States, according to data released Monday by the National Oceanic and Atmospheric Administration. The month featured long, intense heat domes that led to record hot temperatures from the East Coast to the Plains and Southwestern states. NOAA’s temperature records date back to 1895.
By the end of the month, large wildfires were burning in the Pacific Northwest and Canada, mirroring what has been taking place in Europe, which is having its hottest summer on record.
July’s average temperature in the Lower 48 states was 3.3 degrees Fahrenheit above the 20th-century average, NOAA reported. This was about 0.1 to 0.2 degrees warmer than July 1936 and July 2012 — the previous record holders — NOAA stated.
July tends to be the hottest month of the year in most of the US. More than 600 monthly records for highest maximum and minimum temperatures have been set this year in July across the US. There were fewer than 50 monthly records set on the cool side for temperatures. In any given month those should average out to be even. Climate change due to the burning of fossil fuels has altered this pattern.
One feature of the July weather pattern in the US was a seemingly endless series of heat domes that popped up in different parts of the country depending on the contortions of the jet stream. Heat domes act like a lid on a pot, trapping and enhancing hot air beneath them. The jet stream is a narrow corridor of fast-moving air at about 30,000 feet above the Earth’s surface, and it plays a key role in steering and providing energy for weather systems.
