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Just as the freshly vaccinated start to resume barbecues and vacation travel in the coming months, wildfires are likely to force residents of Western states back inside.

The warning signs are written in the parched landscape from New Mexico to California. This time last year, 27 percent of the West was in drought — now that has risen to 76 percent, turning forests into matchsticks.

With the pandemic dominating headlines, the severity of the drought has gotten little attention for how bad it has become. “This one threatens to catch people by surprise who are exhausted by the events of the past year,” said Daniel Swain, a climate scientist at the University of California Los Angeles.

For scientists like Swain, this story is all too familiar. This latest drought is just one episode in a two-decade megadrought in the Western US. Scientists have been warning for decades that rising temperatures are making droughts more frequent and severe and increasing the likelihood of extended megadroughts. Heightened dryness, in turn, is contributing to an increased risk of wildfires.

These trends threaten all Western states, but California faces uniquely severe fire impacts due to its dry summers and population density. Here’s what the state and the rest of the Western US should be bracing for in the coming months and how you can start preparing.

Before we talk about how bad this fire season could get, it’s important to understand just how severe the current drought is. It started building last year when California experienced light winter precipitation and the Southwest had a weak summer rainy season, which typically brings strong monsoon thunderstorms. At the same time, intense heat waves rolled through the whole region.

“If I had to pinpoint one thing that really drove the drought to where we are right now, it was the heat of last summer,” Brian Fuchs, a climatologist at the University of Nebraska’s National Drought Mitigation Center, told Vox in March. These high summer temperatures evaporated the moisture from the soil, further drying out vegetation.

Then, over the past few months, the typical rainy season in California once again came up short. This was due, in part, to La Niña — a weather pattern that occurs roughly every few years when cooler eastern Pacific ocean surface temperatures shift the trade winds, driving storms farther north.

But this drought is also being driven by larger climate trends. Scientists say that it is part of a megadrought — a decades-long dry spell, punctuated by severe droughts. This current megadrought began around 2000, and the majority of the land in the West has been at some level of drought ever since.

And this striking drought bears the fingerprints of climate change. Using tree ring data, a study published in Science in April 2020 found that “anthropogenic warming was critical for placing 2000–2018 on a trajectory consistent with the most severe past megadroughts,” and that megadrought has extended to today.

This fits in with a grim picture laid out by the latest National Climate Assessment, authored by 13 US federal agencies in 2018. Rising temperatures will increase the likelihood of megadroughts in the Southwest and make droughts more frequent and severe, according to the scientific literature cited.

As the latest drought episode within the larger megadrought has deepened, it has left plants and trees desiccated. And the biggest problem is forests.

“When talking about forest fires, for example, the link between dryness and more frequent and severe fires is just crystal clear,” said Swain.

In some ecosystems, the grass and brush growth will be stunted by the lack of moisture, creating less fuel for fires to burn. But that’s only a small silver lining, Swain said, because forests dominate land cover in the West.

The chart below shows how dire the situation has become this year. The current level of vegetation flammability in northern California (blue line) is at near the maximum levels recorded for this time of year (red line).