Ordinarily when air quality alerts are in effect, the air is muggy and oppressive, as if you could cut it with a knife. The overwhelming majority of these alerts happen between June and August.

But Feb. 4, the air was thick with haze, and a Code Orange alert was in effect for the Washington-Baltimore region. This means the air was expected to be unhealthy for sensitive groups such as young children, older adults and those with respiratory conditions.

Read more at Washington Post…