Severe thunderstorm warnings have been issued for parts of New Haven and Middlesex counties.
Severe thunderstorm watches were posted Hartford, Litchfield, Tolland and Windham counties as well.
The storms could contain heavy rain, vivid lightning and gusty winds.
NBC Connecticut's team of meteorologists has issued a First Alert for the storms, which could began to move into the state around 5 p.m. The threat will diminish after 10 p.m.
Fireworks displays around the state could be impacted by the storms this evening.
Areas to the north and west of Connecticut could see more significant storms, including the threat of tornadoes.