What is the longest day of the year?

Arabia Weather - The longest day of the year falls on the summer solstice, which is the day when the day stops increasing and begins to decrease. It is worth noting that the summer solstice differs between the northern and southern hemispheres with a difference of six months. Most of the Earth's population lives in the northern half. As for the date of the summer solstice in the Northern Hemisphere, the longest day of the year falls on the 20th or 21st of June each year. In the Southern Hemisphere, the longest day falls on the 21st or 22nd of December every year.