Memorial Day Weekend – Is It Already Summer?

Memorial Day Weekend is often referred to as the "unofficial" start to the Summer season. Of course, the Summer season “officially” begins June 21st at 6:28am CDT, when the sun is at its northernmost point in the Northern Hemisphere at the Tropic of Cancer. This date marks the summer solstice and is the date that most people think of when it comes to the start of summer. However, while this is true from an astronomical standpoint (known as “Astronomical Summer”), it could be argued that the summer season began weeks ago, and even as early as the first week in May! Now before you think I have gone completely crazy (I may be slightly so but not completely so just yet), let me explain.

There are at least two other beginnings to the “Summer” season that you may or may not have heard about before. The first is what is known as “Meteorological Summer”, and its start date varies a bit from place to place due to latitude, elevation, and proximity to large bodies of water. Meteorological Summer encompasses the warmest 90 days of the year, and it typically begins sometime in the first or second week of June, and ends during the first or second week of September. Sometimes the period used is simply the months of June, July and August. Meteorologists and Climatologists often refer to this period when discussing the summer season in general.

Another ‘beginning’ to the Summer season is called “Solar Summer”, and it encompasses the 90-day period of the year that the amount of solar radiation is at its maximum. In the Northern Hemisphere, this occurs during the period from the first week in May to the first week in August, with the first day of Astronomical Summer as its midpoint. Note that Solar Summer begins about one month before Meteorological Summer, and this occurs because it takes a bit of time to warm the earth, even when the amount of solar energy available to do so is at its peak.

Looks like determining the beginning of summer is a bit more complicated than we thought, right:-)

Mike