The warning is also in effect for all of southern Connecticut, northeast New Jersey and on Long Island, creating dreary, gray conditions.
Dense fog can create a visibility of a quarter mile or less. The warning is through noon but the fog may continue into the afternoon and evening, especially along the coast, the National Weather Service said.
High temperatures Thursday will reach the mid-50s, but showers are expected to move in by afternoon or the evening, the weather service said. Rain is likely overnight with more fog.
The reduced visibility can create hazards for on the road. Drivers should slow down, use low beam headlights and leave plenty of distance ahead in case a sudden stop is needed.
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