SACRAMENTO — A dull haze and the faint smell of smoke from distant blazes have blanketed many California cities for two weeks, forcing summer campers to stay inside, obscuring normally bright skylines, and leaving cars covered with ash.

Smoky air from blowing winds is nothing new in California, but air quality experts say it’s rare for the dirty air to linger for so long, a reality of ever-larger fires that take longer to extinguish.

The haze stretches from the foothills of the Sierra Nevada mountain range to Sacramento and hovers over the San Francisco Bay Area, with most major population centers in between suffering air quality that’s considered dangerous for children, the elderly, and people with asthma or other respiratory conditions.

Kaela Baylis of Sacramento used to take her nearly 2-year-old son outside twice a day but has only gone in the morning the last 10 days.

‘‘He asks to go outside a lot in the afternoon,’’ she said Wednesday as they strolled through a park.

Two major wildfires — one called the Mendocino Complex Fire that is the largest in California history — are burning more than 100 miles north of Sacramento and another huge fire near Yosemite National Park is a little farther to the southeast.

Firefighters made significant progress against the Mendocino Complex for the first time Wednesday but said the blazes will likely persist through September.

The fires have combined to produce unhealthy air that has drifted as far east as Salt Lake City, 450 miles away.

Thursday marked the Sacramento region’s 14th straight ‘‘Spare the Air’’ day, when people are encouraged not to drive and add further pollutants to the air — the longest stretch since at least 2001.

associated press