Winter is the coldest of the four seasons of temperate zones.
"It is the season between Autumn and Spring. Winter is one of the four seasons of temperate zones." "North American calendars go by astronomy and state that winter begins on the winter solstice, and ends on the vernal equinox." "Calculated meteorologically, it begins and ends earlier (typically at the start of the month with the equinox or solstice) and is the season with the shortest days and the lowest temperatures." "Either way, it generally has cold weather and, especially in the higher latitudes or altitudes, snow and ice." "The coldest average temperatures of the season are typically experienced in January in the Northern Hemisphere and in July in the Southern Hemisphere."
"Meteorological winter is the season having the shortest days and the lowest average temperatures. This corresponds to the months of December, January and February, which have the coldest weather and, especially in the higher latitudes or altitudes, snow and ice in the Northern hemisphere. The coldest average temperatures of the season are typically experienced in January in the Northern Hemisphere and in June or July in the Southern Hemisphere. Nighttime predominates the winter season, and in some regions it has the highest rate of precipitation as well as prolonged dampness because of permanent snow cover or high precipitation rates coupled with low temperatures, precluding evaporation. Blizzards often develop and cause many transportation delays. A rare meteorological phenomenon encountered during winter is ice fog, which comprises ice crystals suspended in the air; it occurs only at very low temperatures, below about −30°C (−22°F)."
"Accumulations of snow and ice are mostly associated with winter in the Northern Hemisphere, due to the large land masses there. In the Southern Hemisphere, the more maritime climate and the relative lack of land south of 40°S makes the winters milder; thus, snow and ice are less common in inhabited regions of the Southern Hemisphere. In this region, snow occurs every year in elevated regions such as the Andes, the Great Dividing Range in Australia, and the mountains of New Zealand, and also occurs in the southerly Patagonia region of South America. Snow occurs year-round in Antarctica."
"Meteorologically, the winter solstice, being the day of the year which has fewest hours of daylight, ought to be the middle of the season, but temperature lag means that the coldest period normally follows the solstice, so the season is sometimes regarded (in the USA and England) as beginning at the solstice and ending on the following equinox. In the Northern Hemisphere, depending on the year, this corresponds to the period between December 20 and 21 and March 20 or 21. In Scandinavia, winter traditionally begins on October 14th and ends on the last day of February. In many countries in the Southern Hemisphere, including Australia , New Zealand and South Africa, winter begins on 1 June and ends on 31 August. In Celtic nations such as Ireland (using the Irish calendar) and in Scandinavia, the winter solstice is traditionally considered as midwinter, with the winter season beginning November 1, on All Hallows, or Samhain. Winter ends and spring begins on Imbolc, or Candlemas, which is February 1 or February 2. This system of seasons is based on the length of days exclusively. (The three-month period of the shortest days and weakest solar radiation occurs during November, December, and January in the Northern Hemisphere and May through July in the Southern Hemisphere.)" "Also, many mainland European countries tend to recognize Martinmas, St. Martin's day (November 11), as the first calendar day of winter. The day falls at midpoint between the old Julian equinox and solstice dates. Also, Valentines Day (February 14) is recognized by some countries as heralding the first rites of spring, such as flowers blooming."
"In Chinese astronomy and other East Asian calendars, winter is taken to commence on or around November 7, with the Jiéqì (known as 立冬 lì dōng—literally, "establishment of winter")."
"The three-month period associated with the coldest average temperatures typically begins somewhere in late November or early December in the Northern Hemisphere and lasts through late February or early March. This "thermological winter" is earlier than the solstice delimited definition, but later than the daylight (Celtic) definition. Depending on seasonal lag, this period will vary between climatic regions."
"Cultural influences such as Christmas creep may have led to the winter season being perceived as beginning earlier in recent years."
Northern Hemisphere winter holidays
"The winter months in the Northern Hemisphere is considered a season, often accompanied by festivals and feasts. The winter holiday season is known as a period of time surrounding Christmas that was formed in order to embrace all cultural and religious celebration rather than only Christian celebrations.
Wilson "Snowflake" Bentley's First Snowflake Photograph Jan 15, 1885.
Passing seasons change the habits and moods of people. During the winter months in the northern hemisphere, a gloominess nicknamed "winter blues", "February blahs", "Holiday depression", or doldrums, is informally noted amongst people.