3-19 earth and equinox.jpg

Satellite pictures show how sunlight falls on the Earth at different points during a year. The Earth is shown at the winter solstice on Dec. 21, 2010 (upper left), the spring equinox on March 20, 2011 (upper right), the summer solstice on June 21, 2011 (upper left) and the autumn equinox on Sept. 20, 2011 (lower right).

Today -- June 21, 2015 -- is the summer solstice, or the longest day of the year in the Northern Hemisphere.

The exact moment of the solstice this year was 11:39 a.m. CDT. That is the moment when the Earth tilted the most toward the sun and received the most sunlight.

You may squeeze out a few more minutes of daylight on Sunday depending on where you live.

The farther north you are, the longer your day will be. For example, in Point Barrow, Alaska, one of the northernmost points in the U.S., the sun will be up all day and not set.

In Key West, Fla., the southernmost point in the U.S., the sun will rise on Sunday at 6:39 a.m. and set at 8:19 p.m. EDT, for a day length of 13 hours, 39 minutes and 41 seconds.

Besides being the longest day of the year, the summer solstice also marks the beginning of summer -- at least by some standards. (Meteorological summer began June 1.)

Of course, the longest days of the year do not make for the hottest days of the year.

Through the next couple months, the atmosphere and oceans in the Northern Hemisphere will continue to absorb -- and slowly release -- energy from the sun.

Even though more energy absorption is taking place on the summer solstice, it'll take about another six weeks for us to feel the highest temperatures.

A few other things to know about the summer solstice: