Science, Tech, Math › Science Summer: The Sunshine Season Summer Dates and Typical Weather Share Flipboard Email Print June 20, 2016 is the first day of summer. Don Mason/Blend Images/Getty Images Science Weather & Climate Basics Forecasting Storms & Other Phenomena Chemistry Biology Physics Geology Astronomy by Tiffany Means Tiffany Means has a B.A. in Atmospheric Sciences and Meteorology. She has interned at CNN and written climate reports for NOAA’s National Centers for Environmental Prediction. Updated March 18, 2017 Grab your shorts, swimwear, and SPF 30+ because summer is here! But what does that mean season- and weather-wise? What is summer?Summer, in a nutshell, is the warmest season of the year worldwide (with the exception of one or two tropical locations that also see balmy weather at other times of the year).When is Summer?The Memorial Day holiday is considered to be the "unofficial" start of summer here in the U.S. But summer isn't officially declared until the summer solstice, which occurs every June 20, 21, or 22 in the Northern Hemisphere (December 20, 21, 22 in the Southern Hemisphere). It runs until the next season, fall, begins with the fall equinox.On this date, Earth's axis points its innermost towards the sun. As a result, the sun's direct rays strike at the Tropic of Cancer (23.5° north latitude) and heat the Northern Hemisphere more efficiently than any other region on Earth. This means that warmer temperatures and more daylight are experienced there.When is the summer solstice? See the table below for a list of 2015 to 2020 summer solstice dates. These are the summer start dates you'll see marked on your calendar. But if you want to celebrate summer like a true meteorologist (or just want it to start as soon as possible) you'll want to observe it's start on June 1. Meteorological summer not only begins earlier, but it ends sooner too. It lasts for the 3-month period of June, July, and August (December, January, February in the Southern Hemisphere) and ends on August 30 (February 30). (Astronomical) Summer Solstice Dates YearNorthern HemisphereSouthern Hemisphere2015June 21Dec 222016June 20Dec 212017June 21Dec 212018June 21Dec 212019June 21Dec 222020June 20Dec 21More: Astronomical vs. Meteorological summer - what's the difference?Summer WeatherSummer's most treasured weather type is of course its higher temperatures. But even summer, a seemingly cheerful season, has a severe side.Extreme HeatHeat IndexDroughtsHail stormsThunderstormsOne of the reasons storms become more intense during this time of year is because of the high amount of heat in the atmosphere which works to fuel convection (the heat exchange between the ground and air). Now that you know what summer's about, you're ready to enjoy it's activities, including swimming. But before you cannonball into the nearest pool, I should warn you about this... Continue Reading