Wildfire smoke to ease later Friday before another round arrives this weekend

Forecasters expect another plume of wildfire smoke to spread into northern Illinois late Saturday and Sunday behind a cold front, potentially leading to another stretch of poor air quality

Northern Illinois residents face another day of unhealthy air Friday as Canadian wildfire smoke blankets the region, with forecasters warning that another surge of smoke could arrive this weekend even as thunderstorms return. The Illinois Environmental Protection Agency has issued a Red Air Pollution Action Day through midnight for Rockford and the entire Chicago metropolitan area, citing unhealthy levels of fine particle pollution. Early Friday morning, some air quality monitors briefly reached the “hazardous” category before conditions were expected to gradually improve later in the day.

The National Weather Service said northern Illinois remains on the edge of a dense smoke plume covering much of the Great Lakes region. As southwesterly winds strengthen through the afternoon, the thickest smoke should gradually shift east and northeast, improving visibility and air quality for many communities. The improvement may not last long.

Forecasters expect another plume of wildfire smoke to spread into northern Illinois late Saturday and Sunday behind a cold front, potentially leading to another stretch of poor air quality. Until conditions improve, health officials recommend everyone reduce prolonged or strenuous outdoor activity. Children, older adults, and people with asthma or other respiratory illnesses should avoid extended time outdoors whenever air quality reaches unhealthy levels.

Friday’s forecast also includes warm and humid conditions, with highs in the upper 80s to lower 90s and heat index values nearing 100 degrees in some locations. Scattered showers and thunderstorms are expected to develop this afternoon and evening. While widespread severe weather is not anticipated on Friday, slow-moving storms could produce heavy downpours capable of causing localized flooding, especially where multiple storms move over the same area.

Saturday could bring a more active round of weather as a cold front sweeps south across Illinois. The Storm Prediction Center has placed much of northern Illinois under a Level 1 of 5 severe weather risk, with areas near and south of Interstate 80 under a Level 2 risk. Damaging wind gusts are the primary concern, though isolated hail and localized flooding also will be possible.

Looking ahead, Sunday is expected to be cooler but potentially hazy if the next smoke plume arrives as forecast. Another system capable of producing strong to severe thunderstorms could affect northern Illinois on Monday.