Low water levels are visible next to houseboats anchored at Bidwell Canyon Marina on Lake Oroville on June 01, 2021 in Oroville, California.

Justin Sullivan | Getty Images

Almost three-quarters of the western US is grappling with the worst drought in US Drought Monitor history, as hot and dry conditions will increase the risk of forest fires and water scarcity this summer.

Parts of California, Nevada and Washington State saw stifling triple-digit temperatures last week amid the drought, according to the National Weather Service, with states issuing excessive heat and heat warnings in some areas.

Conditions this spring are much worse than they were a year ago. In fact, nearly half of the continental US is experiencing a moderate to exceptional drought, which is the most significant spring drought in the country since 2013, according to scientists from the National Oceanic and Atmospheric Administration.

An aerial photo on June 1, 2021 in Oroville, California shows the remains of a house and trees that were burned by a recent forest fire near the steep banks of Lake Oroville.

Justin Sullivan | Getty Images

The US Drought Monitor, a team of academics and government scientists, was founded about two decades ago. It is updated every Thursday to show the location and intensity of the drought across the country.

In California, which is frequently hit by droughts and massive forest fires, state reservoirs are currently 50% lower than they should be, according to an Associated Press report.

Farmers in the northwest are also grappling with increasing drought damage to crops and having difficulty irrigating fields when the water level drops.

“72% of the western US is currently in a ‘severe’ drought or worse. This is now the largest severe drought in recorded history,” climate scientist and activist Eric Holthaus wrote in a tweet. “We are in a climate emergency.”

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Climate change means that droughts and other extreme weather conditions such as hurricanes, forest fires, become more frequent and intense.

Researchers also say that rising temperatures have pushed the American Southwest into a decade-long mega-drought, which has resulted in a decline in snow cover, lake and river levels, and groundwater availability, among other things.

“After two years of water in arid conditions, both California and Nevada are now 100% dry,” said an update to NOAA’s National Integrated Drought Information System on Friday.

“And given the dire drought conditions, rapidly decreasing snow cover and low reservoir levels, concerns about the forest fire season are growing,” it said.