Code Red Air Quality Alert Issued for All Of Pennsylvania as Wildfire Smoke Returns

All of Pennsylvania is under a code red air quality alert Wednesday as smoke from the Canadian wildfires returns.

While it's not expected to be quite as bad for southeastern Pennsylvania as the round earlier this month that drove air quality levels to "hazardous" levels, it will still be enough to make the air "unhealthy" for all groups.

Western parts of the state were expected to get hit hardest, prompting the state Department of Environmental Protection to issue the code red alert for that region first, but the smoke progressed further east overnight than projected, according to the forecast from AirNow.gov. Around 10 a.m., the DEP expanded the code red to the entire state.

"Air quality conditions degraded overnight as more smoke from the wildfires pushed into Pennsylvania from the Great Lakes region," according to the forecast.

Fine particulate concentrations from the smoke will increase over southeastern Pennsylvania by midday, with the highest levels expected later in the day "as the smoke continues to advance south and eastward," according to the forecast.

When a code red alert is issued, everyone should reduce prolonged outdoor activity or heavy exertion. Sensitive groups, including the elderly, young children, and those with breathing difficulties, should avoid all outdoor activities, according to the DEP.

Smoke from the wildfires is expected to linger over Pennsylvania through Friday, according to the DEP.