Thousands of homes in Northern California remain threatened by the nation’s largest wildfire as unstable weather creates a high danger of new blazes erupting across the West.

Weekend thunderstorms across the northern Sierra didn’t produce much rain, instead whipping up winds and unleashing lightning strikes that that bedeviled the more than 6,000 firefighters trying to contain the month-old Dixie Fire amid temperatures forecast to top 100 degrees (38 Celsius).

When Tom Larsen thinks of the Dixie Fire in Northern California, he thinks about better modeling.

Larsen, the senior director for content strategy for catastrophe modeler CoreLogic Inc., pointed to some grim facts about the ongoing Dixie blaze: It’s already the second largest wildfire in recorded state history, and over the past two years five of the state’s top seven largest fires have occurred – things he blames on forestry management, climate change, more homes being built in the wildland-urban interface and of course the massive drought plaguing the Western U.S.

“What we’re seeing now in the last few years is loss history’s insufficient,” Larsen said. “The history that we’ve seen is insufficient to look forward and understand the risk.”

Thick smoke that held down winds and temperatures began to clear Sunday from the scenic forestlands of Northern California as firefighters battling the largest single wildfire in state history braced for a return of fire-friendly weather.

The winds weren’t expected to reach the ferocious speeds that helped the Dixie Fire explode in size last week. But they were nonetheless concerning for firefighters working in unprecedented conditions to protect thousands of threatened homes.

It could be days before officials will be able to assess the damage done to a small town by California’s largest wildfire, one of dozens of blazes scorching lands across the U.S. West.

Over the weekend, the massive Dixie Fire roared through the remote Northern California community of Indian Falls. The blaze had already leveled at least 16 houses and other structures, but a new damage estimate wasn’t immediately available because flames were still raging in the mountain area on Monday.

“Fire behavior has been so unpredictable, it hasn’t been safe for inspectors to go in to work,” said Mitch Matlow, a fire spokesman. “Until things settle down, we won’t know the extent of what’s burned.”

A lightning strike likely ignited a 2020 wildfire in California’s Sierra National Forest, but the U.S. Forest Service said Friday it could not determine an official cause of the fire.

September’s Creek Fire burned 600 square miles and spread so quickly that hundreds of Labor Day holiday campers had to be rescued by a series of harrowing helicopter flights. All 214 campers were delivered safely.

Investigators did not rule out arson and lit cigarettes as the cause, but said there were no illegal marijuana grow sites nearby that could have started the fire. Forest service officials said an “undetermined” status is not uncommon with a fire this complex.

California power company Pacific Gas and Electric said on Wednesday it would bury 10,000 miles of power lines in high-risk fire zones as a safety measure after its equipment caused multiple destructive wildfires over several years.

The utility, which called the project a multi-year initiative, maintains more than 25,000 miles of overhead distribution power lines in the highest fire-risk zones, or more than 30% of its total distribution overhead system, according to the company.

The move by PG&E comes days after it said its equipment may have been involved in the start of a recent wildfire in Sierra Nevada, according to a filing by PG&E to regulators published on the internet by a San Francisco Chronicle journalist.

Pacific Gas & Electric reported to California utility regulators that its equipment may have been involved in the start of a fire burning in the Sierra Nevada that is threatening hundreds of homes.

PG&E said in a report Sunday to the California Public Utilities Commission that a repairman responding to a circuit outage on July 13 spotted blown fuses in a conductor atop a pole, a tree leaning into the conductor and fire at the base of the tree.

The utility said its system showed around 7 a.m. that the Cresta Dam off Highway 70 had lost power but because of the steep, rough terrain, the worker sent to check it couldn’t reach the area until nearly 5 p.m.

It may have been around 2017 when a true sense of urgency donned on insurers, public officials, residents and regulators in wildfire-prone California, as fires destroyed or damaged more than 10,000 structures in the state, a higher tally than the previous nine years combined.

In terms of property damage, 2017 was the most destructive wildfire season on record in California at the time, with 9,133 fires burning more than 1.2 million acres, and it was after 2017 that the word “mitigation” seemed to appear more prominently and more often in public messaging about wildfires – along with news of warnings about rising homeowners insurance rates, increasing non-renewals, and of course climate change.

Cal/OSHA is cautioning California employers to be prepared to protect workers from unhealthy air due to wildfire smoke.

When workers are at risk form unhealthy air from wildfires, California’s protection from wildfire smoke standard requires employers to take steps such as changing the location of work operations, modifying work schedules or providing proper respiratory protection like N95 respirators.

According to CalFire, there have been over 4,000 wildfire incidents so far in California in 2021 and more than 100 structures have been damaged. Smoke from these wildfires contains chemicals, gases and fine particles that can harm health.

One of the most harmful hazards comes from breathing fine particles in the air (called PM2.5), which can reduce lung function, worsen asthma or other existing heart and lung conditions, and cause coughing, wheezing and difficulty breathing, according to Cal/OSHA.

Firefighters struggled to contain an exploding Northern California wildfire under blazing temperatures as another heat wave blanketed the West, prompting an excessive heat warning for inland and desert areas.

Death Valley in southeastern California’s Mojave Desert reached 128 degrees Fahrenheit on Saturday, according to the National Weather Service’s reading at Furnace Creek. The shockingly high temperature was actually lower than the previous day, when the location reached 130 F.

If confirmed as accurate, the 130-degree reading would be the hottest high recorded there since July 1913, when Furnace Creek desert hit 134 F, considered the highest measured temperature on Earth.