When is the longest day of the year? Everything you need to know about the summer solstice

As we move deeper into Summer, the evenings stay lighter for longer. But almost as soon as Summer arrives, so too does the summer solstice, meaning the days shorten as we tumble back towards winter.

Here's everything you need to know about the astronomical turning point.

What is the summer solstice?

The summer solstice - which is also known as midsummer - is the moment when the Earth's rotational axis, or the geographical "pole" on which it spins, is most greatly inclined toward the star that it orbits.

This happens twice each year (once in each hemisphere), when the Sun reaches its highest position in the sky as seen from either the North or South Pole.

The same dates in the opposite hemisphere are referred to as the winter solstice.

When is it this year - exactly?

The summer solstice always occurs between June 20 and June 22 in the Northern Hemisphere, six months on from the winter solstice, which falls between December 20 and December 23.

In 2018, the Northern Hemisphere's summer solstice falls on June 21.

The exact moment of the summer solstice will be 11:07 BST, but the colloquial term "midsummer" refers to the entire day on which the solstice occurs.

What does it mean for me?

The summer solstice gives us the 'longest' day of the year, which simply means that the sun will be above the horizon for more time than it is on any other day of the year.

Considering the 'length' of the day has been increasing in increments of only about two minutes a day since January, you'll hardly notice the difference.

But it could be an excuse to throw that big summer bash, or invite everyone round for a barbecue.