The changing seasons are based on Earth's position in its orbit around the sun, the astronomical season. There's another type of season used by meteorologists known as the meteorological season.
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00:00 We know there are four seasons in the calendar year.
00:03 What many may not know is that there are also two separate seasonal transitions,
00:08 astronomical and meteorological.
00:10 Astronomical seasons change due to the Earth's tilt on its axis during its orbit around the sun.
00:16 Astronomical seasons are fully dependent on the Earth's relationship with the sun.
00:21 When the sun's direct rays strike the equator at a perfect 90.00 degree angle,
00:27 we're looking at one of the equinoxes, the spring or fall equinox.
00:32 And when the direct rays of the sun strike the Tropic of Cancer to the north
00:35 or the Tropic of Capricorn to the south, we're looking at the solstices.
00:38 The exact date of solstices and equinoxes varies,
00:42 which is why the first days of astronomical seasons change.
00:45 Typically, they take place around the 21st of March, June, September and December.
00:51 There's no exact date for the changing seasons
00:53 because Earth's orbit around the sun does not take exactly 365 days.
00:58 It takes roughly 365 and a quarter days.
01:02 This is also why we have leap years every four years.
01:05 The length of meteorological seasons are more consistent,
01:08 so meteorologists use them to calculate seasonal statistics more accurately.
01:12 For weather purposes and meteorology data comparisons and so forth,
01:17 we tend to look at kind of a broad brush approach to the seasons.
01:21 December, January and February tend to typically be
01:24 approximately the three coldest months of the year,
01:26 so we call those three months meteorological winter.
01:29 On a similar note, June, July and August are approximately
01:33 the warmest three months of the year in most areas,
01:35 so we call that meteorological summer.
01:38 For AccuWeather, I'm Kevin Coskren.