tick ring footage
Californians evacuate as wildfires rage
01:36 - Source: CNN
CNN  — 

Wildfires are nothing new to California.

In fact, they’re a natural part of the state’s landscape, officials say. So the state continues to take measures each year to combat the threats and devastation of flames.

But in the past two years, California has experienced the deadliest and most destructive wildfires in its history, according to the California Department of Forestry and Fire Protection.

In 2017, wildfires ravaged more than 1.5 million acres, killing 44 people and burning more than 11,000 structures.

Last year, more than 1.6 million acres were burned, over 23,000 structures damaged or destroyed and 93 people died, CAL FIRE reported. Eighty-five of them were killed when the Camp Fire devastated northern portions of the state. It was the deadliest blaze in the state’s history.

This year again, two different parts of the state have been damaged by raging infernos. Here’s how they compare to years past:

Powerful winds always play a role

Strong, dry winds are almost always the reason why the wildfires in the state spread and move so quickly.

“Wind increases the supply of oxygen which results in the fire burning more rapidly,” CAL FIRE spokeswoman Mary Eldridge said. “It also removes the surface fuel moisture which increases the drying of fuel.”

A cluster of devastating wildfires in October 2017 – including the 51,000-plus acre Atlas Fire in Napa and Solano counties and the 56,000-plus acre Nuns Fire in Napa and Sonoma counties – were all aided by strong winds, with some gusts reaching more than 70 mph.

This year, similar hurricane-force winds were driving the flames in Northern California, with the highest gusts in Sonoma county reaching a whopping 93 mph Sunday, meteorologists said.

These are known as Diablo Winds.

“Diablo winds are offshore wind events that flow northeasterly over Northern California’s Coast Ranges, often creating extreme danger for the San Francisco Bay Area,” the Fire Weather Research Laboratory said.

They tend to hit in highest frequency during October, the lab said.

Past fires were also fueled by drought

There was one major factor that played a role in the 2017 and 2018 fires: they were fueled by drought.

A multi-year drought across California ended months before the October 2017 fires. While the rain helped vegetation throughout the state bloom, that foliage soon withered after a dry summer.

That, coupled with strong winds, created the perfect storm.

The Tubbs fire, the Atlas fire and the Redwood/Potter fires torched about 20,000 acres in Northern California in 12 hours alone.

But fire season is getting longer

There’s a major development for wildfires that’s becoming more apparent.

“The fire season in California and across the West is starting earlier and ending later each year,” CAL FIRE said.

Fire season has increased by 75 days across the Sierras and “seems to correspond with an increase in the extent of forest fires across the state,” the department said.


Officials credit climate change.

“Warmer spring and summer temperatures, reduced snowpack, and earlier spring snowmelt create longer and more intense dry seasons that increase moisture stress on vegetation and make forests more susceptible to severe wildfire,” CAL FIRE said.

And while the number of wildfires may not be going up, the size of fires is increasing, the World Meteorological Organization reported last year.

Since the 1970s, California wildfires have increased in size by eight times and the annual burned area has grown by nearly 500%, CNN meteorologist Rob Shackelford said.

It’s easy to see why, when there are 129 million dead trees in California alone – a side effect of rising temperatures that cause western forests to dry out, the meteorological organization said.