* WHAT. Heat index values 95 to 100. * WHERE. Northern Middlesex and Northern New London Counties. * WHEN. From noon today to 8 PM EDT Thursday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

The Connecticut Department of Environmental Protection has issued an Air Quality Action Day for Ground Level Ozone, from 11 AM this morning to 11 PM EDT this evening. An Air Quality Action day means that Ground Level Ozone concentrations within the region may approach or exceed unhealthy standards. For additional information, please visit the Connecticut Department of Energy and Environmental Protection website at: https://portal.ct.gov/deep

The Massachusetts Department of Environmental Protection has issued an Air Quality Alert for Ground Level Ozone, from 11 AM this morning to 11 PM EDT this evening. An Air Quality Alert means that Ground Level Ozone concentrations within the region may approach or exceed levels that are Unhealthy for Sensitive Groups. Air is unhealthy for sensitive children and adults, such as those with asthma, lung or heart disease, and older adults. Sensitive children and adults should limit prolonged outdoor activity. For additional information, please visit the Massachusetts Department of Environmental Protection website at: https://mass.gov/orgs/massachusetts-department-of-environmental- protection

* WHAT. Heat index values up to 101 expected. * WHERE. Portions of central, eastern, northeastern, southeastern, and western Massachusetts and northern Rhode Island. * WHEN. From 8 AM this morning to 7 PM EDT Thursday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 100 expected. * WHERE. In Connecticut, Hartford CT, Tolland CT, and Windham CT Counties. In Massachusetts, Eastern Hampden MA, Eastern Hampshire MA, Western Hampden MA, and Western Hampshire MA Counties. * WHEN. From 8 AM this morning to 7 PM EDT Friday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Dangerously hot conditions with heat index values up to 105 expected. * WHERE. Portions of south central, southwest, and western Maine and central, northern, and southern New Hampshire. * WHEN. From noon today to 8 PM EDT this evening. * IMPACTS. Heat related illnesses increase significantly during extreme heat and high humidity events. * ADDITIONAL DETAILS. Warm overnight low temperatures in the 70s will result in greater cumulative heat stress.

* WHAT. Heat index values up to 100 expected. * WHERE. Portions of south central, southwest, west central, and western Maine and central, northern, and southern New Hampshire. * WHEN. From noon today to 8 PM EDT this evening. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS. Warm overnight low temperatures in the 70s will result in greater cumulative heat stress.

The New Hampshire Department of Environmental Services has issued an Air Quality Alert for ozone from 11 AM to 11 PM EDT Wednesday. The New Hampshire Department of Environmental Services is predicting unhealthy air quality in the above-mentioned counties. Sensitive individuals include children and older adults; anyone with lung disease such as asthma, emphysema, and bronchitis; and people who are active outdoors. Even healthy individuals may experience mild health effects and should consider limiting strenuous or prolonged outdoor activities. For additional information, please visit the New Hampshire Department of Environmental Prediction website at, https://www4.des.state.nh.us/airdata/