When Does Winter Start?

Can you believe that it is the 1st December and according to the Met Office it is the start of winter.

With the onslaught of Storm Arwen at the weekend bringing with it gale-force winds battering our coastlines delivering the dreaded sleet and snow I think we all realised that winter was upon us.

The meteorological definition of the seasons means that the year is split into four seasons which coincide with the Gregorian calendar. Apparently this makes it easier for forecasting and monthly statistics.


Astronomical Winter

In 2021 the astronomical winter begins on 21 December and is the Winter Solstice in the Northern Hemisphere and ends on 20 March 2022. The Winter Solstice is also known as the 'shortest day' of the year as there are fewer hours of sunlight. After the Winter Solstice the good news is that the days start to get longer until the Summer Solstice which is the longest day of the year.

The reason why we have seasons is related to astronomy and planetary science. The earth's axis is tilted as it orbits the sun and takes about 365 days. This means that one half of the earth is pointed away from the sun and the other is pointed towards it at the time of the solstice. Each orbit is an eclipse. In one year the earth travels about 584 million miles or 940 million km.