In North America, the Summer solstice began on June 21, 2013 at 1:04 A.M. EDT
Sol + stice derives from a combination of Latin words meaning "sun" + "to stand still." As the days lengthen, the sun rises higher and higher until it seems to stand still in the sky.
As a major celestial event, the Summer Solstice results in the longest day and the shortest night of the year. The Northern Hemisphere celebrates in June, but the people on the Southern half of the earth have their longest summer day in December.
Severe thunderstorms are expected today across parts of the northern Plains and Upper Mississippi Valley today and tonight. A few tornadoes and large hail will mainly impact the northern Plains before transitioning to a damaging wind threat across parts of the Upper Mississippi Valley later this evening and overnight.