The Massachusetts Department of Environmental Protection has issued an air quality alert across much of the state, due to high ozone levels. The alert will be in effect from 11 a.m. to 11 p.m. Monday, Aug. 11.

The National Weather Service reported an air quality alert at 8:43 a.m. on Monday in effect until 11 p.m. for Northern Worcester and Southern Worcester as well as Middlesex, Essex, Hampshire, Hampden,

The heat index, or the "feels like" temperature, is predicted to be in the mid to high 90s for the first half of the week. Boston issued previous emergencies in June and July.