It’s going to be hot as hell in California—again. The state, as well as Arizona and Nevada, are expected to see a record breaking heat wave this Labor Day weekend.
These extreme temperatures are expected to blanket the Southwest just two weeks after the region saw another heat wave smashed records. The intense heat and accompanying lightning storm sparked more than 900 wildfires in California, including the second and third largest fires in state history (both are still blazing). The fires also introduced us to the term “gigafire,” used to denote more than 1 million acres burned.
Now, California is about to get a redo of the heat portion of last month’s catastrophe. In fact, according to the National Weather Service (NWS)—which called the coming heat “dangerous”—some areas might get even hotter than they did then.
On Saturday, temperatures are predicted to climb to 15 to 20 degrees Fahrenheit (27 to 36 degrees Celsius) above normal or higher, with some parts of the Los Angeles area expected to reach up to 115 degrees Fahrenheit (46.1 degrees Celsius). Overnight lows are only expected to drop to the 70s and 80s, making for extremely uncomfortable sleeping weather. The NWS has issued excessive heat warnings across most of the state as well as parts of Arizona, Nevada, and Oregon.
All of this heat could spark even more fires across the region, which has already seen 1.5 million acres burned down since August 15. That’s especially true because the heat is expected to be caused by a high-pressure atmospheric area moving over the western U.S., created by changes in the powerful weather-steering winds known as the jet stream. This high pressure system is expected to also bring dry conditions, which could turn California’s forests into a tinderbox. While there’s no storms that sparked with the state fire agency called a “lightning siege” this time around, most fires in the West are started by human activities so the risk remains high.
Smoke and haze are also expected to persist throughout the weekend, creating hazardous air quality. Data shows that wildfires last month caused parts of the Southwest to have the dirtiest air in the world. Air quality issues are longstanding in California, but amid the spread of respiratory virus covid-19, those concerns are even more pronounced. NWS also warned that this weekend’s heat and fires could bring energy outages to the state, as more people close their windows to keep the smoke out and turn on air conditioners. That means some may be forced to weather the heat and fires without power, another unfortunate similarity to the last heat wave.
Thankfully, this heat wave is not expected to last as long as that last one. Temperatures will start climbing Friday and begin to tick back down on Monday.
Extreme heat waves and dangerous wildfires are both tied to the climate crisis. The world is getting hotter, drier, and more flammable. California has borne the brunt of those trends, but other parts of the world are also suffering as the climate changes. To avoid even more hellish conditions down the road, world leaders need to act to reduce greenhouse gas emissions.