June 20 2025 - A solstice is an event in which earth’s poles are most extremely inclined toward or away from the sun, at about 23.5 degrees. Solstices happen twice per year, June and December, marking the change of seasons to summer and winter. During the June solstice, the sun is directly over the Tropic of Cancer at noon and it marks the Northern Hemisphere astronomical beginning of summer with the longest daylight. In the Southern Hemisphere, it marks the beginning of astronomical winter, with the day having the shortest period of daylight. More