As the United States celebrated Independence Day, a brutal and potentially historic heatwave sent temperatures soaring across the country, putting over 134 million people under heat alerts. The extreme weather event is expected to continue unabated for the next week, with little chance of relief even after dark.
Forecasters warn that the high overnight temperatures and the long-lasting duration of the extreme event will increase the danger, posing additional risks to human health and the rapid spread of wildfires. “This is going to be a severe, prolonged, potentially record-breaking heatwave,” said Dr. Daniel Swain, a climate scientist.
Temperatures are expected to spike up to 115F (46C) in California’s interior, the desert southwest, and parts of Oregon, according to the National Weather Service (NWS). The heat will spread north into Oregon and Washington, sending highs soaring throughout the western region. All-time heat records could be broken in several locations, including Las Vegas and Redding, California.
The NWS has cautioned anyone in affected areas to stay inside, stay hydrated, and check on vulnerable neighbors. “Intense and long duration heat building in the west will be extremely dangerous and potentially deadly if not taken seriously,” federal forecasters said. “The multi-day nature of the heat and record warm overnight temperatures will cause heat stress to build in people without adequate cooling.”
Dangers are pronounced even in areas that won’t rank among the hottest this week, including the typically mild San Francisco Bay Area, where many residences and businesses are not equipped with air conditioning. “It is very likely that we will see a number of heat-related fatalities throughout this event,” forecasters with the NWS Bay Area wrote.
US Heatwave GripsResidents are being urged to take the event seriously, cautioning all to take extra care during outdoor activities connected to Independence Day celebrations. The extreme heatwave is also raising the risk of wildfires during Fourth of July celebrations when they are more likely to spark because of fireworks, barbecues, and other flammables.
Firefighters across California are already battling multiple blazes, including one that broke out on Tuesday and quickly swept across more than 3,000 acres. The Thompson fire is burning near the city of Oroville, about an hour outside Sacramento, California’s capital. Nearly 30,000 residents have been ordered to evacuate.
The heat arrived with gusty, dry winds in the northern part of the state, where the utility Pacific Gas and Electric implemented public safety power shutoffs in parts of 10 counties to prevent wildfires from being ignited by downed or damaged electrical wires.
California has had a spate of spring and early summer wildfires, thanks to an abundantly wet winter that left terrains across California coated in grasses that were primed to burn once the weather warmed. The excessive heat will only dry terrains and vegetation further, adding to the threat of an active wildfire season for months to come.
While this heatwave may be the worst to hit the US west so far this year, it likely will not be the last. The human-caused climate crisis is expected to cause extreme heat events that last longer and are larger and more intense, and experts have said this week’s weather is part of a troubling trend. This year is already on track to become the hottest on record.
Extreme heat is the most deadly type of weather-related disaster, and the toll is already on the rise. Forecasters warn that the dangerous weather conditions this week will pose health risks to the majority of the population, especially those unable to access cooling.
As the heatwave continues to grip the nation, residents are left to seek relief where they can. Katherine Powers, who is homeless, sought refuge in the shade of Cathedral Square in Sacramento, California, sipping sparkling water and resting her bare feet on the shaded sidewalk. “I’m just going to go to a park with a water fountain just to stay cool, stay in the shade and just keep pouring water on me, basically,” she said. “There’s not too much that I can do.”