Today we mark the summer solstice, the longest day of the year, signalling the start of astronomical summer.

A solstice occurs when one of Earth’s poles reaches its maximum tilt towards the Sun. For those of us in the Northern Hemisphere, it will be the longest of the year, but for those in the Southern Hemisphere, it’s the opposite.

On the summer solstice, the sun travels its longest path after rising, reaching its northernmost point. The precise time of the summer solstice on June 21st is at 4:24 a.m. ET.

The summer solstice is over 9 hours longer in daylight length than the winter solstice! Make sure you make the most of the additional daylight!

The sun is also at its strongest on the solstice, which means you need to take extra precaution in the sun, especially as the UV Index is forecast to reach high levels across some parts of the U.S.

While meteorological summer began on June 1st, and will last until August 31st, astronomical summer relies on the tilt of the Earth and its rotational axis, which will end on September 22nd, when the autumn equinox occurs.