This St. Patrick's Day in southwestern Connecticut will be enveloped in dense fog early this morning before the sun begins o'smilin' across the region by midday.

The daytime high temperature is expected to rise to the upper-50s, and a wind from the east will be clocked at between 5 and 8 mph.

Overnight, fog is expected to settle in again as the temperature falls to a low in the low-40s.

There will be areas of fogginess tomorrow morning, clearing by about 9 a.m. Cloudy conditions will also gradually give way to the sun by midday as the temperature rises to the low-60s. Clouds return at night and the low temperature will be in the mid-40s.

On Monday, there will be areas of fog before 9 a.m. and skies for the rest of the day are expected to be mostly cloudy, with a high in the mid-60s. Nighttime will be cloudy and the low temperature will be about 5o degrees.

The outlook for Tuesday -- the first official day of spring -- is for sunny skies and a high in the mid-60s, according to the weather service.