The first day of summer is finally here!
Summer officially kicked off on Monday, June 21, 2010,Â at 7:28 a.m. ET, which means the beginning of the summer solstice and the longest day of the year, at least in the Northern Hemisphere.Â Â According to National Geographic, the summer solstice is a result of the Earth’s north-south axis being tilted 23.5 degrees relative to the sun. The tilt causes different amounts of sunlight to reach different regions of the planet.
On the summer solstice, the Northern Hemisphere receives more sunlight than on any other day of the year, but that doesn’t mean the first day of summer is also the hottest day of summer.Â To learn more about the science behind the summer solstice, click here.