On or around June 21 is the time when the Sun is at its highest or most northerly point in the sky in the Northern Hemisphere and when we receive the most hours of daylight. If you live in the Southern Hemisphere it is the reverse, so you will be having “Winter Solstice.”
Picture above: The rise of the sun is seen at a 2,300-year-old structure in Peru, between Tower 1 and Cerro Mucho Malo at the June solstice, 2003, viewed from the western solar observatory. The sunrise position at the solstice has shifted to the right approximately 0.3° from the year 300 BC. Credit: Ivan Ghezzi
The summer solstice occurs each year exactly when the Earth’s axial tilt is most inclined towards the sun at its maximum of 23° 26′. Though the summer solstice is an instant in time, the term is also colloquially used like Midsummer to refer to the day on which it occurs.
Except in the polar regions (where daylight is continuous for many months during the spring and summer), the day on which the summer solstice occurs is the day of the year with the longest period of daylight. Thus the seasonal significance of the Summer solstice is in the reversal of the gradual shortening of nights and lengthening of days. The summer solstice occurs in June in the Northern Hemisphere and in December in the Southern Hemisphere.