WHAT IS THE SUMMER SOLSTICE?
In the Northern Hemisphere, the June solstice occurs when the Sun reaches both its highest and northernmost points in the sky. (In contrast, the June solstice in the Southern Hemisphere is when the Sun is at its lowest point in the sky.)
The word “solstice” comes from Latin solstitium—from sol (Sun) and stitium (standing), reflecting the fact that on the solstice, the Sun appears to stop moving in the sky as it reaches its northern- or southernmost point. After the solstice, the Sun appears to reverse course and head back in the opposite direction.
The timing of the June solstice is not based on a specific calendar date or time; it all depends on when the Sun reaches its northernmost point from the equator. Therefore, the June solstice won’t always occur on the same day.
In temperate regions, we notice that the Sun is higher in the sky throughout the day, and its rays strike Earth at a more direct angle, causing the efficient warming we call summer. Because the sun is highest in the sky on this day, you’ll notice that your shadow (at noon) is the shortest it will be all year.
Summer Solstice is scheduled for June 21, 2018.