Dozens of wildfires are burning in Oregon and Washington after thunderstorms brought thousands of lightning strikes, igniting blazes across the region’s hot, dry landscape.

Robin DeMario, a spokeswoman at the Northwest Interagency Coordination Center, said on Saturday that firefighters were working on at least 30 large fires that started around the time of the thunderstorms on Wednesday and Thursday. Many of those fires were caused by lightning, Ms. DeMario said. For others, the cause has not been determined.

The fires are burning while smoke covers parts of many states in the Midwest and northeastern United States, much of it from wildfires in Canada. Hot, dry and windy conditions forecast for the coming week, as well as another potential round of thunderstorms with little rain, could lead to more fires and make the current blazes harder to fight.

Larry O’Neill, the state climatologist of Oregon, said the state had been bracing for an active wildfire season because much of Oregon was in either severe or extreme drought.

He said that he saw dozens of smoke columns as he drove down a highway in central Oregon after a thunderstorm on Thursday.

“It was very surreal,” Dr. O’Neill said. Lightning-ignited wildfires happen in Oregon, he added, “but I’ve never seen it so intense and so widespread.”

Here’s what to know about the lightning and the fires in the Pacific Northwest:

How unusual is lightning in the Pacific Northwest?

Thunderstorms raced across nearly every corner of Oregon and into parts of Washington Wednesday night into Thursday, delivering more than 14,000 lightning strikes, according to data from the National Lightning Detection Network, a private network of lightning sensors. Some of the highest concentrations of lightning occurred in the northern half of Oregon.

The storms were moving too fast to bring enough rain to any one area to soak the vegetation and ease the wildfire risk. Most locations received only a tenth to a third of an inch of rain from the storms.

The Pacific Northwest gets a lightning outbreak about once a year, according to Hannah Chandler-Cooley, a meteorologist with the National Weather Service office in Portland, much less than some other parts of the country such as the Southeast.

The Pacific Northwest’s location fronting the Pacific Ocean is the main reason it doesn’t get more thunderstorms. Thunderstorms form when there is warm, moist air near the ground and cooler air above, creating an unstable atmosphere. In the Pacific Northwest, there’s no shortage of cool air, with it constantly flowing onshore off the Pacific Ocean, rarely allowing temperatures at the surface to warm up enough for the development of storms.

What fires have been caused by lightning?

The largest fire since the thunderstorm appears to be the Kaiser Canyon fire, on the Colville Indian Reservation. It has burned more than 37,000 acres in Washington and forced evacuations.

The fire is burning grass, bitter brush and downed trees amid erratic winds in steep, rocky terrain, said Bethany Osgood, a spokeswoman for the Northeast Washington Interagency Incident Management Team 3.

Another large fire is the Porcupine Ridge fire, near Condon, Ore., a rural community with around 700 residents, which has burned more than 15,000 acres as of early Saturday.

Because the fires ignited in the middle of summer, there’s plenty of time for them to burn, said Dmitri Kalashnikov, a postdoctoral research fellow at the University of California, Merced, who studies lightning and lightning-caused fires.

“Here in the Northwest, it’s about to get hot again, so it’s just going to continue to be favorable burning conditions for these fires,” Dr. Kalashnikov said.

Does climate change play a role?

Because weather is so variable, any one set of wildfires or storms can’t be attributed directly to climate change, said Erica Fleishman, who directs the Oregon Climate Change Research Institute at Oregon State University.

“But there are reliable projections suggesting that, as climate changes, both the number of lightning strikes will increase, and the probability that a lightning strike will ignite a wildfire will increase,” she said.

That’s because higher temperatures, a lower snowpack in the winter and drier summers can make fuel on the ground easier to burn, she said.

“This isn’t a weird weather pattern, necessarily,” Dr. Fleishman said. “It’s a weather pattern that likely will become more common. And, again, the greatest risk is that you have this weather pattern coinciding with conditions on the ground where any lightning strike is more likely to ignite a fire.”

What should residents do to protect themselves?

Follow any evacuation warnings and fire restrictions issued by local officials.

“We don’t need any new human-ignited fires to add to the mix,” Ms. DeMario said, adding that she encouraged people on public land to “be especially careful with their vehicles, with anything that may have potential to cause a spark that may start a fire.”

As smoke disperses across the region, be mindful of air quality.

In areas with unhealthy air quality, stay inside if possible and take precautions to make the air inside your home safer. If you have to be outside, consider wearing an N-95 or similar mask.