Air-quality readings from Iqair.com shortly after 1 p.m. Sunday.

Smoke from regional wildfires has once again drifted into the Rogue Valley, leading Jackson County Public Health to issue an air-quality advisory through Monday evening, the county announced early afternoon Sunday.

“Wildfire smoke is a complex mixture of air pollutants harmful to human health,” the county’s Health & Human Services Department said in a release. “Exposure to air pollutants in wildfire smoke can irritate the lungs, cause inflammation, alter immune function and increase susceptibility to respiratory infections.”

The thick haze arrives as the National Weather Service in Medford predicts high Sunday temperatures of about 94 degrees, with an expected cooling down to 59 Sunday night. The weather service predicts more smoke in the coming days as Monday sees a high of about 86 Monday, followed by a low of 54 that night.

Live air-quality readings at Iqair.com shortly after 1 p.m. Sunday showed unhealthy pollution levels along Interstate 5 between Eagle Point and Ashland and west into Jacksonville.

Air pollution in Medford, Eagle Point, Jacksonville, Phoenix and Ashland was at “unhealthy” levels, while the air in Talent was deemed “unhealthy for sensitive groups,” the website said.

The county’s public health department shared tips on how to stay safe during wildfire smoke:

• Be aware of smoke concentrations in your area and avoid the places with the highest concentrations.
• Stay indoors with doors and windows closed. Whether you have a central air-conditioning system or a room unit, use high-efficiency filters to capture fine particles from smoke. Ask an air-conditioning professional what type of high-efficiency filter your air conditioner can accept.
• Create a “clean room” in your home. Choose a room with no fireplace and as few windows and doors as possible, such as a bedroom. Use a portable air cleaner in the room.
• Maintain good indoor air quality by avoiding smoking inside, using gas, wood‐burning stoves or furnaces, aerosol sprays, frying or broiling meat, burning candles or incense, and vacuuming. The Oregon Health Authority has an air conditioner and air filter deployment program for people living in Jackson County who are currently or recently eligible for medical assistance.
• Temporarily leave the area and go to an area with cleaner air. Go to public indoor areas with cleaner air space.
• Drink lots of water. Staying hydrated can keep your airways moist, which will help reduce symptoms of respiratory irritation such as scratchy throat, running nose, and coughing.
• Have a supply of NIOSH-approved respirators and learn how to use them. If you choose to wear a respirator, select a particulate respirator marked with the word “NIOSH.” If it has an “N,” “R,” or “P” along with the number 95, 99, or 100 printed on it, it is appropriate to use. Oregon OSHA has videos in Spanish and English on how to properly wear a respirator.