Wildfires in California have burned a record 4 million acres since the start of 2020, charring more land in the past nine months than during the previous three years combined. The results are devastating. The more than 8,200 blazes since January have killed 31 people and destroyed more than 8,400 homes and buildings, the California Department of Forestry & Fire Protection said Sunday. The number of acres burned is more than double the previous record, set in 2018.

The fires have been stoked by searing-hot weather, tinder-dry brush left after years of drought, powerful winds, and other conditions that state officials say have been made worse by climate change. In August, a record-breaking heatwave triggered the state’s first rotating power outages since the 2001 energy crisis. Smoke from the blazes has drifted as far as Europe.

This weekend, firefighters face another round of heat as they battle an inferno in Northern California’s wine country. The Glass Fire has charred more than 63,000 acres and destroyed at least 800 homes and buildings. Temperatures in the city of Napa were forecast to hit 90 Fahrenheit on Sunday.

Four people have now been killed in a separate blaze, the Zogg Fire, burning further north in Shasta County, authorities said Thursday. It’s charred more than 56,000 acres.