Summer Solstice

In the northern hemisphere, the longest day of the year when the Sun is farthest north. The summer solstice marks the first day of the season of summer. In the southern hemisphere, this is your winter solstice, marking the shortest day of the year. The declination of the Sun on the (northern) summer solstice is known as the tropic of cancer (23° 27′).

http://scienceworld.wolfram.com/astronomy/SummerSolstice.html