* WHAT. Dense fog will reduce visibility to less than 1 NM. * WHERE. Fire Island Inlet NY to Montauk Point NY out 20 nm. * WHEN. Until noon EDT Monday. * IMPACTS. Low visibility will make navigation difficult.

* WHAT. Heat index values up to 97 expected. * WHERE. In Connecticut, Hartford CT, Tolland CT, and Windham CT Counties. In Massachusetts, Southern Worcester MA, Central Middlesex MA, Western Norfolk MA, Northern Bristol MA, and Western Plymouth MA Counties. In Rhode Island, Northwest Providence RI and Southeast Providence RI Counties. * WHEN. From noon Monday to 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 96 expected. * WHERE. In Massachusetts, Eastern Hampden MA County. In Rhode Island, Eastern Kent RI and Western Kent RI Counties. * WHEN. From noon today to 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 97 expected. * WHERE. In Connecticut, Hartford CT, Tolland CT, and Windham CT Counties. In Massachusetts, Southern Worcester MA, Central Middlesex MA, Western Norfolk MA, Northern Bristol MA, and Western Plymouth MA Counties. In Rhode Island, Northwest Providence RI and Southeast Providence RI Counties. * WHEN. From noon today to 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Dense fog will reduce visibility to less than 1 NM. * WHERE. Fire Island Inlet NY to Montauk Point NY out 20 nm. * WHEN. Until noon EDT Monday. * IMPACTS. Low visibility will make navigation difficult.

* WHAT. Heat index values of 95 to 100 expected. * WHERE. In Connecticut, Northern Fairfield, Northern Middlesex, Northern New Haven, Northern New London, Southern Fairfield, and Southern New Haven Counties. In New York, Northern Nassau and Northwest Suffolk Counties. * WHEN. From noon Monday to 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses. * ADDITIONAL DETAILS. The highest heat index values will be generally in the afternoon and early evening hours.

* WHAT. Heat index values up to 98 expected. * WHERE. In Connecticut, Northern Fairfield, Northern Middlesex, Northern New Haven, Northern New London, Southern Fairfield, and Southern New Haven Counties. In New York, Northern Nassau and Northwest Suffolk Counties. * WHEN. From noon today to 8 PM EDT Tuesday. * IMPACTS. High temperatures and high humidity may cause heat illnesses.

* WHAT. Dense fog will reduce visibility to 1 NM or less. * WHERE. Fire Island Inlet NY to Montauk Point NY out 20 nm, and Long Island Sound East of the Mouth of the Connecticut River. * WHEN. Until noon EDT today. * IMPACTS. Low visibility will make navigation difficult. * ADDITIONAL DETAILS. The fog may persist through the day.

* WHAT. For the Dense Fog Advisory, visibility less than one mile in dense fog. For the Heat Advisory, heat index values up to 97 expected. * WHERE. In Massachusetts, Northern Bristol MA and Western Plymouth MA Counties. In Rhode Island, Eastern Kent RI, Northwest Providence RI, Southeast Providence RI, and Western Kent RI Counties. * WHEN. For the Dense Fog Advisory, until 8 AM EDT this morning. For the Heat Advisory, from noon today to 8 PM EDT Tuesday. * IMPACTS. Low visibility could make driving conditions hazardous. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. For the Dense Fog Advisory, visibility less than one mile in dense fog. For the Heat Advisory, heat index values up to 97 expected. * WHERE. In Massachusetts, Northern Bristol MA and Western Plymouth MA Counties. In Rhode Island, Eastern Kent RI, Northwest Providence RI, Southeast Providence RI, and Western Kent RI Counties. * WHEN. For the Dense Fog Advisory, until 8 AM EDT this morning. For the Heat Advisory, from noon today to 8 PM EDT Tuesday. * IMPACTS. Low visibility could make driving conditions hazardous. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Heat index values up to 96 expected. * WHERE. In Connecticut, Hartford CT, Tolland CT, and Windham CT Counties. In Massachusetts, Southern Worcester MA, Central Middlesex MA, Western Norfolk MA, and Eastern Hampden MA Counties. * WHEN. From noon today to 8 PM EDT Tuesday. * IMPACTS. Hot temperatures and high humidity may cause heat illnesses.

* WHAT. Visibility one quarter mile or less in dense fog. * WHERE. In Massachusetts, Eastern Plymouth MA, Southern Bristol MA, and Southern Plymouth MA Counties. In Rhode Island, Bristol RI, Newport RI, and Washington RI Counties. * WHEN. Until 8 AM EDT this morning. * IMPACTS. Low visibility could make driving conditions hazardous.

* WHAT. Visibility one quarter mile or less in dense fog. * WHERE. In Massachusetts, Barnstable MA, Dukes MA, and Nantucket MA Counties. In Rhode Island, Block Island RI. * WHEN. Until noon EDT today. * IMPACTS. Low visibility could make driving conditions hazardous.

Fog will continue to develop through the early morning hours with some of it becoming dense, reducing visibilities to a quarter mile or less. Locations right along the immediate coast will be more likely to experience dense fog. Motorists should be prepared for quickly changing visibilities. Slow down, allow for extra space between vehicles and use your low beam headlights in the fog. A Dense Fog Advisory may be needed should the dense fog become widespread.