what time does summer officially start
But when the sun sets in the western sky Monday, it will be the culmination of the longest day of the year. June 20 is the summer solstice, marking the official start of the 2016 summer season â and the day with the most amount of sunlight all across the northern hemisphere. Full 'strawberry moon' on the way.
The summer solstice (June 21st. the longest day in the northern hemisphere) is the start of Summer. The autumnal equinox (September 23rd. when day/night are again equal) is the start of Autumn. The winter solstice (December 22nd. the shortest day in the northern hemisphere) is when winter starts.