“With so many fires burning across a wide region, it’s important to remember that there is a lot of variability in the specific factors at play for a given fire, from the ignition source to what kind of landscape is burning to the local conditions spreading the flames. However, there are some common factors that tie many of these blazes together and make them exceptional.”
“Record heat this summer baked much of the western United States, with states like California experiencing their hottest August on record. Many cities and counties across the West experienced record or near-record heat throughout the summer and into September. The summer was capped with a punishing heat wave that settled across the region in August and September and drove temperatures well into triple digits.
It has also been extremely dry in California, Oregon, and Washington this summer, with large sections of each state under “severe drought” conditions and some areas reaching “extreme drought.”
That heat and dryness turned grasses, shrubs, and trees into easy tinder, ready to ignite at the slightest spark.” …
“The vast majority of wildfires in the United States are ignited by human sources — power lines, cigarette butts, machinery, or, in the case of one infamous recent fire, a gender reveal stunt. But a strange dry lightning storm near the San Francisco Bay Area in August led to more than 11,000 lightning strikes and triggered more than 300 fires in its wake. The causes of many other fires across the region are still being investigated.
The record-breaking weather comports with what scientists expect as the climate changes, and in many of the burning areas, the climate has already shifted in ways to worsen fire risk.”