The period when winter starts differ in the Northern and Southern Hemisphere. In the Northern Hemisphere it is from December 20 up to March 21. In the Southern Hemisphere this would be around June 20 and culminates on September 22.
The beginning and end dates may vary a day or two. The coldest month in the Northern Hemisphere is usually January.
The most prevalent trait is cold weather. In countries like the US and Canada, the season is marked by the presence of heavy snowfall. In other countries it is characterized by rain instead. The season is also marked by typhoons and hurricanes in some parts of Asia. When winter starts the nights are longer too. The afternoons are longer and much colder.
Other weather phenomenon associated with this season is ice fog. This can take place when the temperatures go below -25 C or – 20 F. This phenomenon usually takes place in the Northern Hemisphere.
Effect on Animals
Animal behavior is greatly affected by the coming season. One of the most common traits is that of migration. This can be seen in a lot of animals particularly birds. Some species of butterflies also migrate when the season approaches. The migration does not occur among all bird species though.
When winter starts some animals go into hibernation. What these animals do is sleep during the period. This behavior is most apparent in bears. However it can also be seen in other species like snakes, bats and other reptiles.
Changes in animal behavior include accumulation of food. This activity can be seen among squirrels raccoons and beavers. Another sign of the coming season is that the color or fur changes. This can be seen in the snowshoe hare, the white tailed jackrabbit and ptarmigan.
Effects on Plants
With the exception of the flowering plum, almost all plants and flowers perish during this season. Trees lose their leaves and some branches as well. Even when winter starts, the trees will be able to grow leaves again because their roots survive.
Although the period for the season is defined in the Northern and Southern Hemispheres, countries have their own calendars and occasion that state when the season “officially” begins. For instance, in Ireland the season officially commences on the first day of November. In other European countries the season commences on the 11th of November. In China the official date is on the 7th, also in the same month.
In Culture and the Arts
In mythology, the season is traditionally associated with death, spring being the resurrection. This is exemplified in the Greek tale of Persephone. The same theme is used in the poems of Robert Frost and the works of C.S. Lewis and Vivaldi.
Recent studies have also shown that some people are susceptible to disorders brought by the coming of the season. These cases are termed seasonal affective disorders or SAD.
The time when winter starts is different in various parts of the world. Due to the changing climates, the occurrence and duration of the season may gradually be also subject to change soon.