Vog is expected to stick around through the weekend, according to the National Weather Service.
Forecaster Pete Donaldson said southeasterly winds are blowing volcanic emissions from the Big Island toward Oahu and the neighbor islands. That pattern is expected to persist through Saturday and possibly longer, he said. Tradewinds are expected to gradually return early next week.
Vog causes irritation to the eyes, nose, throat and lungs, especially in those with respiratory conditions like asthma and emphysema.
The American Lung Association-Hawaii Chapter recommend individuals with breathing problems to stay indoors and use an air conditioner set to recirculate indoor air to prevent outdoor air from entering the home. Individuals sensitive to vog also should have their medications on hand, stay hydrated and avoid outdoor physical activity.