Topline
Excessive heat warnings are in place for much of the west coast and southern United States heading into the Fourth of July weekend, when millions of people will experience triple-digit temperatures and nearly two dozen states will be under heat warnings and watches.
A man walks during a record heat wave in Phoenix, Arizona on July 18, 2023.
Key Facts
The National Weather Service has issued excessive heat warnings for 11 states—Arizona, Arkansas, California, Louisiana, Mississippi, Nevada, Oklahoma, Oregon, Tennessee, Texas and Washington—for various parts of the holiday week and weekend.
Excessive heat warnings are isued when the maximum heat index temperature is expected to be 105 degrees or higher and night-time air temperatures will not drop below 75 degrees.
In Oklahoma, Tennessee, East Texas, Mississippi, Arkansas, and Louisiana, the warning is already in effect and will last through the evening of the Fourth of July.
The warnings will start in Arizona, Nevada and Oregon on the Fourth and last through the weekend, and in Washington state a warning is in effect from Saturday through next Tuesday.
Temperatures are expected to reach into the 90s in even more states, including Utah, Colorado, New Mexico, Pennsylvania, Ohio, West Virginia, Kentucky, South Carolina, Florida, North Carolina, Georgia and Alabama.
In California's Bay Area,where several daily heat records were broken Tuesday, NBC News reported, an excessive heat warning is already in effect and will last through next Tuesday.
The record-breaking hot streak is expected to continue for up to 12 days and could bring the longest stretch of extreme temperatures seen in the region in almost two decades.
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Crucial Quote
"Heat is the No. 1 rated weather-related killer in the U.S. By this weekend, it is very likely that we add to that statistic if preparations are not taken seriously," the National Weather Service San Francisco Bay Area tweeted.
What To Watch For
If heat records are broken. Death Valley could break the world heat record over the weekend, the San Francisco Chronicle reported, with temperatures possibly topping 130 degrees. Records could also be broken in Oregon, Wisconsin and in the Southwest. The NWS has warned against going outside where excessive heat watchers are in effect and suggested people in those states both avoid alcoholic, sugary or caffeinated drinks and eat small meals frequently, rather than few larger meals.
Key Background
Last year the Fourth of July was recorded as the hottest day in over 10,000 years when the global average temperature hit 17.1 degrees Celsius, or 62.62 degrees Fahrenheit. The record was tied on July 6 and 7, 2023, and those days remain the single hottest ever recorded, according to the University of Maine’s Climate Change Institute. The summer of 2023 was Earth's hottest summer since record keeping began in 1850 and was likely the hottest in the last 2,000 years, according to Climate Central. Forecasts for July 2024 predict well above average temperatures across almost all of the United States, according to NOAA, but it’s unclear if this July will break last year’s records. Global temperatures reached a record high for the 12th consecutive month in May, according to NOAA.
Tangent
The Biden administration on Tuesday said it plans to require new protections from extreme heat for workers in the United States as temperatures continue to rise. Employers will be required to ensure workers have access to shade and water, as well as provide breaks for those working in extreme heat, under the proposed regulations for the Occupational Safety and Health Administration. The new rules would be required when the heat index reaches 80 degrees or higher. More than 2,300 people are estimated to have died from heat-related deaths in the U.S. last year, and global temperatures are continuing to rise as climate change worsens.
