Arlington County and the rest of the D.C. metropolitan area is under a Code Orange alert today (Friday) for its air quality.

With temperatures and humidity expected to build today and continue through the Fourth of July holiday, the Metropolitan Washington Council of Governments issued its alert, warning that sensitive groups could be affected and should avoid strenuous activity or outdoor exercise.

More from MWCOG and the National Weather Service:

The Metropolitan Washington Council of Governments in association with Maryland Department of the Environment, Virginia Department of Environmental Quality, and District Department of Environment has issued a Code ORANGE Air Quality Alert Friday for the DC metro area.

A Code Orange Air Quality Alert means that air pollution concentrations within the region may become unhealthy for sensitive groups. Sensitive groups include children, people suffering from asthma, heart disease or other lung diseases and the elderly. The effects of air pollution can be minimized by avoiding strenuous activity or exercise outdoors.

For more information on ground-level ozone and fine particles… visit www.cleanairpartners.net.

MWCOG forecasts that the air quality will drop down to moderate levels this weekend.

Image via Environmental Protection Agency’s AirNow service