Statewide ‘Code Purple’ Air Quality Alert issued for Friday. What it means for Centre County
AI-generated summary reviewed by our newsroom.
- State DEP issued a statewide Code Purple alert (”very unhealthy” air) for Friday
- State College area recorded an AQI of 211 on Friday morning, within Code Purple range.
- Forecasts project AQI falling to about 150 Saturday and below 101 by Sunday.
On the heels of Centre County’s hazy Thursday skies, the area will again be under an air quality alert Friday after a statewide “Code Purple” alert was formally issued by the state Department of Environmental Protection.
A “Code Purple” alert is the second-highest level of the Air Quality Index, developed by the U.S. Environmental Protection Agency, and signifies a “very unhealthy” level of air pollution. In a news release, the state DEP suggested all residents move Friday’s activities indoors due to blanketing smoke from wildfires in Canada and Minnesota.
“During Code Purple Air Quality Alerts all residents should avoid long or intense outdoor activities, and sensitive groups such as children, elderly residents, and those with respiratory illnesses should avoid all outdoor activities,” the department wrote. “All residents are encouraged to move activities indoors.”
The state DEP acknowledged that conditions could vary throughout the day, from one area to the next. On Thursday, despite the state DEP issuing a “Code Red” alert — the third-highest level of the index — the State College area still found itself under the index’s most severe level (”hazardous” maroon) after 3 p.m., based on a local air pollution device.
According to that same monitoring device, the Air Quality Index on Friday morning stood on the lower end of “Code Purple,” meaning the morning’s conditions were significantly improved from Thursday — but still unsafe.
The Air Quality Index measures the density of five pollutants on a standard scale of 0-500 in six color-coded categories, ranging from moderate green (0-50) to hazardous maroon (301+). The State College area reached levels as high as 404 Thursday and, as of 7 a.m. Friday, stood at 211.
Based on forecasts from the state DEP, Centre County should see some relief over the weekend. Saturday is expected to have an Air Quality Index of about 150, which would be characterized as “unhealthy for sensitive groups.” The EPA noted that, under such levels, the general public is less likely to be affected — but children, the elderly and those with respiratory illnesses could experience health effects from being outdoors.
The state DEP’s forecast says that Sunday should return to moderate levels under a 101 index. Historically, State College’s average index sits below a 30.
For more information and updated conditions in the State College area, which boasts an air pollution monitor, the state DEP encourages residents to check AirNow.gov.
Air Quality Index chart
An overview of the six color-coded categories of the Air Quality Index can be found below and was taken from AirNow:
- Green (Good) — 0 to 50 — Air quality is satisfactory, and air pollution poses little or no risk.
- Yellow (Moderate) — 51 to 100 — Air quality is acceptable. However, there may be a risk for some people, particularly those who are unusually sensitive to air pollution.
- Orange (Unhealthy for Sensitive Groups) — 101 to 150 — Members of sensitive groups may experience health effects. The general public is less likely to be affected.
- Red (Unhealthy) — 151 to 200 — Some members of the general public may experience health effects; members of sensitive groups may experience more serious health effects.
- Purple (Very Unhealthy) — 201 to 300 — Health alert: The risk of health effects is increased for everyone.
- Maroon (Hazardous) — 301 and higher — Health warning of emergency conditions: Everyone is more likely to be affected.
This story was originally published July 17, 2026 at 8:11 AM.
