GUINDA, Calif. — Evacuations were ordered as dry, hot winds fueled a wildfire burning out of control Sunday in rural Northern California, sending a stream of smoke some 75 miles south into the San Francisco Bay Area.

The fast-moving blaze that broke out Saturday in western Yolo County charred at least 34 square miles of dry brush and threatened more than two dozen structures in ranchland northwest of Sacramento.

No injuries were reported and the exact number of people evacuated was unclear.

It was one of two major wildfires in the northern part of the state, where temperatures were soaring, humidity was dropping, and winds were steady.

A blaze burning for several days to the west in Lake County jumped containment lines Saturday, prompting additional evacuation orders. That fire was more than 70 percent contained after charring about 22 square miles of brush.

Smoke from the Yolo County fire was contributing to poor air quality in Napa, Sonoma, San Mateo, and San Francisco counties, according to the National Weather Service.

The smoky haze settling on areas to the south and west was rattling nerves near wine country communities that were devastated by deadly wildfires late last year.

‘‘A lot of friends and family were texting today and saying they were having some PTSD,’’ said Savannah Kirtlink, who evacuated her Napa home during the blazes in December.

She took photos of the smoke moving in this weekend and told KGO-TV she empathized with her neighbors to the north who were forced to flee their homes.

In Arizona on Saturday, 19 firefighters who died five years ago when they were overrun by a wildfire in a brush-choked canyon in Arizona were honored at a memorial service.

The event in Prescott included bell tolls and the reading of the names of the Granite Mountain Hotshots who died June 30, 2013, in Yarnell, northwest of Phoenix.

A moment of silence was observed at the time of their deaths.

Associated Press