Full Moon on the Summer Solstice
June 20, 2016, is the first day of summer, the day of the Summer Solstice AND a full moon, too!
The coincidental "same day" full moon and solstice timing last happened in 1948. And it will not happen again until 2062, according to EarthSky.org. By the way, the official start of Summer is at 4:34 p.m. MDT, when the sun is directly above the latitude line called the Tropic of Cancer.
The day is marked by the longest amount of daylight for the year, which includes the the Midnight Sun above the Arctic Circle, where the sun never dips below the horizon today. We'd assume there are plenty of parties going on in Alaska and Canada.
By the way, the June moon is called the "Strawberry Moon." Full moon has already happened (at about 5 a.m. today) and moonrise tonight in the Bitterroot Valley should be in the 9 p.m. hour, depending on which mountains are in your way.