As most of us are breathing a sigh of relief that 2020 is just about over, many meteorologists are doing the same thing. The year featured devastating wildfires and hurricanes, tornadoes, derechos and flooding, and just about everything else the atmosphere has to offer. Wildfires and hurricanes were relentless and especially punishing, setting records for the amount of real estate they affected in the Lower 48, while killing dozens. Supercharged by human-caused climate change, they signaled trouble for the future as the climate warms further.

A year filled with extreme weather meant a hefty price tag: Insurance firm Aon estimates that at least 25 separate billion-dollar weather disasters unfolded across the United States this year.

“The United States has endured one of its costliest years for weather disasters on record and is facing an economic toll that will exceed $100 billion,” Steven Bowen, head of catastrophe insight at Aon, wrote in an email.

Fire season

Smoke extent from fires in the Lower 48. Large wildfires are also shown. (AirNow)

Fueled by record heat and parched vegetation, fanned by howling winds and, at times, sparked by blitzes of lightning, the West was plagued by an onslaught of devastating wildfires that began in June and continued into December.

The fires occurred in a region that is trending hotter, drier and more susceptible to large blazes due to climate change. In California, which saw a record wildfire season, a study published in August showed that the frequency of fall days with extreme fire-weather conditions has already more than doubled since the 1980s.

In early September, when fires exploded amid howling land-to-sea winds not only in California but also Oregon and Washington, Nick Nauslar, a meteorologist at the National Interagency Fire Center in Boise, Idaho, said the eruption surpassed anything in the modern record.

“Multiple fires made 20+ mile runs in 24-hours over the last few days in California, Oregon, and Washington,” he said in an email. “Most of these fires are making massive runs in timber and burning tens of thousands of acres and in some cases 100,000+ acres in one day. The shear amount of fire on the landscape is surreal, and no one I have talked to can remember anything like it.”

In mid-September, the smoke from these blazes led to hazardous levels of air pollution all along the West Coast and covered almost the entirety of the Lower 48, even reaching D.C.