Layers of drift smoke from fires in Central and Northern California blanketed the Riverside metropolitan area Thursday, blocking the sun in what was tantamount to heavy cloud cover.
“Riverside is experiencing drift smoke due to the fires north of us,” the Riverside Fire Department said via social media. “We have no active fires at this time.”
The message was echoed by Cal Fire-San Bernardino County, which sent an alert stating, “There is smoke looking towards mountains in San Bernardino. We have no active fires. This is likely drift smoke from the Northern California fires.”
The South Coast Air Quality Management District issued an advisory through Friday afternoon acknowledging the presence of heavy smoke “in the upper atmosphere,” but said air quality index levels remain “good” throughout the region.
“Elevated AQI levels are expected in mountain areas … until Friday afternoon,” according to the agency. “To help keep indoor air clean during periods of poor air quality, close all windows and doors and run your air conditioner or air purifier. If possible, do not use whole house fans or swamp coolers that bring in outside air.”
The poorest air quality over the next day was expected in the Hemet-San Jacinto Valley, as well as portions of the Coachella Valley, according to the SCAQMD.
In areas affected by wildfire smoke, the AQI may reach Unhealthy for Sensitive Groups levels or higher from Thursday afternoon until Friday afternoon, the SCAQMD said.
According to Cal Fire, there are three active wildfires in the Sierra Nevada Mountains, and farther north, there are at least a half-dozen wildland blazes.