Temperate season | |
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![]() Blooming flowers and trees in spring | |
Northern temperate zone | |
Astronomical season | 21 March – 21 June |
Meteorological season | 1 March – 31 May |
Solar (Celtic) season | 1 February – 30 April |
Southern temperate zone | |
Astronomical season | 23 September – 22 December |
Meteorological season | 1 September – 30 November |
Solar (Celtic) season | 1 August – 31 October |
Summer Spring ![]() Winter |
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Spring, also known as springtime, is one of the four temperate seasons, succeeding winter and preceding summer. There are various technical definitions of spring, but local usage of the term varies according to local climate, cultures and customs. When it is spring in the Northern Hemisphere, it is autumn in the Southern Hemisphere and vice versa. At the spring (or vernal) equinox, days and nights are approximately twelve hours long, with daytime length increasing and nighttime length decreasing as the season progresses until the Summer Solstice in June (Northern Hemisphere) and December (Southern Hemisphere).
Spring and "springtime" refer to the season, and also to ideas of rebirth, rejuvenation, renewal, resurrection and regrowth. Subtropical and tropical areas have climates better described in terms of other seasons, e.g. dry or wet, monsoonal or cyclonic. Cultures may have local names for seasons which have little equivalence to the terms originating in Europe.
Meteorologists generally define four seasons in many climatic areas: spring, summer, autumn (fall), and winter. These are determined by the values of their average temperatures on a monthly basis, with each season lasting three months. The three warmest months are by definition summer, the three coldest months are winter, and the intervening gaps are spring and autumn. Meteorological spring can therefore, start on different dates in different regions.
In the US and UK, spring months are March, April, and May. [1] [2]
In Australia [3] and New Zealand, [4] [5] spring begins on 22nd or 23rd of September and ends on 21 December.
In Ireland, following the Gaelic calendar, spring is often defined as February, March, and April. [6] [7]
In Sweden, meteorologists define the beginning of spring as the first occasion on which the average 24 hours temperature exceeds zero degrees Celsius for seven consecutive days, thus the date varies with latitude and elevation.
In Brazil, spring months are September, October, November.
In the Northern Hemisphere (e.g. Germany, the United States, Canada, and the UK), [8] the astronomical vernal equinox (varying between 19 and 21 March) can be taken to mark the first day of spring with the summer solstice (around 21 June) marked as first day of summer. By solar reckoning, Spring is held to begin 1 February until the first day of Summer on May Day, with the summer solstice being marked as Midsummer instead of the beginning of Summer as with astronomical reckoning.
In Persian culture the first day of spring is the first day of the first month (called Farvardin) which begins on 20 or 21 March.
In the traditional Chinese calendar, the "spring" season ( 春 ) consists of the days between Lichun (3–5 February), taking Chunfen (20–22 March) as its midpoint, then ending at Lixia (5–7 May). Similarly, according to the Celtic tradition, which is based solely on daylight and the strength of the noon sun, spring begins in early February (near Imbolc or Candlemas) and continues until early May (Beltane).
The spring season in India is culturally in the months of March and April, with an average temperature of approx 32 °C. [9] Some people in India especially from Karnataka state celebrate their new year in spring, Ugadi.
The beginning of spring is not always determined by fixed calendar dates. The phenological or ecological definition of spring relates to biological indicators, such as the blossoming of a range of plant species, the activities of animals, and the special smell of soil that has reached the temperature for micro flora to flourish. These indicators, along with the beginning of spring, vary according to the local climate and according to the specific weather of a particular year.[ citation needed ] In England, Wales and Northern Ireland, the National Trust runs the #BlossomWatch campaign, which encourages people to share images of blossom with one another, as an early indicator of the arrival of the season. [10]
Some ecologists divide the year into six seasons. In addition to spring, ecological reckoning identifies an earlier separate prevernal (early or pre-spring) season between the hibernal (winter) and vernal (spring) seasons. This is a time when only the hardiest flowers like the crocus are in bloom, sometimes while there is still some snowcover on the ground. [11]
During early spring, the axis of the Earth is increasing its tilt relative to the Sun, and the length of daylight rapidly increases for the relevant hemisphere. The hemisphere begins to warm significantly, causing new plant growth to "spring forth," giving the season its name. [14]
Any snow begins to melt, swelling streams with runoff and any frosts become less severe. In climates that have no snow, and rare frosts, air and ground temperatures increase more rapidly.
Many flowering plants bloom at this time of year, in a long succession, sometimes beginning when snow is still on the ground and continuing into early summer. [15] In normally snowless areas, "spring" may begin as early as February (Northern Hemisphere) or August (Southern Hemisphere), heralded by the blooming of deciduous magnolias, cherries, and quince. [16] Many temperate areas have a dry spring, and wet autumn (fall), which brings about flowering in this season, more consistent with the need for water, as well as warmth. Subarctic areas may not experience "spring" at all until May.
While spring is a result of the warmth caused by the changing orientation of the Earth's axis relative to the Sun, the weather in many parts of the world is affected by other, less predictable events. The rainfall in spring (or any season) follows trends more related to longer cycles—such as the solar cycle—or events created by ocean currents and ocean temperatures—for example, the El Niño effect and the Southern Oscillation Index.
Unstable spring weather may occur more often when warm air begins to invade from lower latitudes, while cold air is still pushing from the Polar regions. Flooding is also most common in and near mountainous areas during this time of year, because of snow-melt which is accelerated by warm rains. In North America, Tornado Alley is most active at this time of year, especially since the Rocky Mountains prevent the surging hot and cold air masses from spreading eastward, and instead force them into direct conflict. Besides tornadoes, supercell thunderstorms can also produce dangerously large hail and very high winds, for which a severe thunderstorm warning or tornado warning is usually issued. Even more so than in winter, the jet streams play an important role in unstable and severe Northern Hemisphere weather in springtime. [17]
In recent decades, season creep has been observed, which means that many phenological signs of spring are occurring earlier in many regions by around two days per decade.[ citation needed ]
Spring in the Southern Hemisphere is different in several significant ways to that of the Northern Hemisphere for several reasons, including:
Carnival is practiced by many Christians around the world in the days before Lent (40 days, without Sundays, before Easter). It is the first spring festival of the new year for many. [19]
Easter is the most important religious feast in the Christian liturgical year. [20] Christians believe that Jesus was resurrected from the dead on the "third day" [note 1] (two days after his crucifixion), and celebrate this resurrection on Easter Day, two days after Good Friday. Since the Last Supper was a Passover Seder, the date of Easter can be calculated as the first Sunday after the start of Passover. This is usually (see Passover below) the first Sunday after the first full moon following the spring equinox. The date of Easter varies between 22 March and 25 April (which corresponds to between 4 April and 8 May in the Gregorian Calendar for the Eastern and Oriental Orthodox Churches using the Julian Calendar). In this celebration, the children do an easter egg hunt.
The First of May is the date of many public holidays. [21] In many countries, May Day is synonymous with International Workers' Day, or Labour Day, which celebrates the social and economic achievements of the labour movement. As a day of celebration, the holiday has ancient origins, and it can relate to many customs that have survived into modern times. Many of these customs are due to May Day being a cross-quarter day, meaning that (in the Northern Hemisphere where it is almost exclusively celebrated) it falls approximately halfway between the spring equinox and summer solstice. In the Celtic tradition, this date marked the end of spring and the beginning of summer.
The Passover begins on the 15th day of the month of Nisan, which typically falls in March or April of the Gregorian calendar on the night of a full moon after the northern spring equinox. [22] However, due to leap months falling after the vernal equinox, Passover sometimes starts on the second full moon after vernal equinox, as in 2016. Jews celebrate this holiday to commemorate their escape from slavery in Egypt as described in the book of Exodus in the Torah. Foods consumed during Passover seders, such as lamb and barley, are tied to springtime seasonal availability. In this celebration, children recite the Four Questions during the seder and hunt for the afikoman afterwards.
The Western Christian season encompassing the triduum of All Saints' Eve (Halloween), All Saints' Day (All Hallows') and All Souls' Day are observed in the spring in the Southern hemisphere.
Autumn, also known as fall in American English and Canadian English, is one of the four temperate seasons on Earth. Outside the tropics, autumn marks the transition from summer to winter, in September or March. Autumn is the season when the duration of daylight becomes noticeably shorter and the temperature cools considerably. Day length decreases and night length increases as the season progresses until the Winter Solstice in December and June. One of its main features in temperate climates is the striking change in colour for the leaves of deciduous trees as they prepare to shed.
A solar equinox is a moment in time when the Sun crosses the Earth's equator, which is to say, appears directly above the equator, rather than north or south of the equator. On the day of the equinox, the Sun appears to rise "due east" and set "due west". This occurs twice each year, around 20 March and 23 September.
A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countries, the seasons of the year are determined by the solstices and the equinoxes.
Summer is the hottest of the four temperate seasons, occurring after spring and before autumn. At or centred on the summer solstice, daylight hours are longest and darkness hours are shortest, with day length decreasing as the season progresses after the solstice. The earliest sunrises and latest sunsets also occur near the date of the solstice. The date of the beginning of summer varies according to climate, tradition, and culture. When it is summer in the Northern Hemisphere, it is winter in the Southern Hemisphere, and vice versa.
Winter is the coldest season of the year in polar and temperate climates. It occurs after autumn and before spring. The tilt of Earth's axis causes seasons; winter occurs when a hemisphere is oriented away from the Sun. Different cultures define different dates as the start of winter, and some use a definition based on weather.
Seasonal lag is the phenomenon whereby the date of maximum average air temperature at a geographical location on a planet is delayed until some time after the date of maximum insolation. This also applies to the minimum temperature being delayed until some time after the date of minimum insolation.
Birkat Hachama refers to a rare Jewish blessing that is recited to the Creator, thanking God for creating the sun. The blessing is recited when the sun completes its cycle every 28 years on a Tuesday at sundown. Jewish tradition says that when the Sun completes this cycle, it has returned to its position when the world was created. Because the blessing needs to be said when the sun is visible, the blessing is postponed to the following day, on Wednesday morning.
The climate of Chicago is classified as hot-summer humid continental. All four seasons are distinctly represented: Winters are cold and often see snow with below 0 Celsius temperatures and windchills, while summers are warm and humid with temperatures being hotter inland, spring and fall bring bouts of both cool and warm weather and fairly sunny skies. Annual precipitation in Chicago is moderate and relatively evenly distributed, the driest months being January and February and the wettest July and August. Chicago's weather is influenced during all four seasons by the nearby presence of Lake Michigan.
The September equinox is the moment when the Sun appears to cross the celestial equator, heading southward. Because of differences between the calendar year and the tropical year, the September equinox may occur anytime from September 21 to 24.
The March equinox or northward equinox is the equinox on the Earth when the subsolar point appears to leave the Southern Hemisphere and cross the celestial equator, heading northward as seen from Earth. The March equinox is known as the vernal equinox in the Northern Hemisphere and as the autumnal equinox in the Southern Hemisphere.
The term Uttarāyaṇa is derived from two different Sanskrit words – "uttara" (North) and "ayana" (movement) – thus indicating a semantic of the northward movement of the Sun on the celestial sphere. This movement begins to occur a day after the winter solstice in December, which occurs around 22 December and continues for a six-month period through to the summer solstice around June 21. This difference is because the solstices continually precess at a rate of 50 arcseconds per year due to the precession of the equinoxes, i.e. this difference is the difference between the sidereal and tropical zodiacs. The Surya Siddhanta bridges this difference by juxtaposing the four solstitial and equinoctial points with four of the twelve boundaries of the rashis.
The summer solstice, also called the estival solstice or midsummer, occurs when one of Earth's poles has its maximum tilt toward the Sun. It happens twice yearly, once in each hemisphere. For that hemisphere, the summer solstice is the day with the longest period of daylight and shortest night of the year, when the Sun is at its highest position in the sky. Within the Arctic circle or Antarctic circle, there is continuous daylight around the summer solstice. The opposite event is the winter solstice.
Lists of holidays by various categorizations.
The June solstice is the solstice on Earth that occurs annually between 20 and 22 June according to the Gregorian calendar. In the Northern Hemisphere, the June solstice is the summer solstice, while in the Southern Hemisphere it is the winter solstice. It is also known as the northern solstice.
The December solstice, also known as the southern solstice, is the solstice that occurs each December – typically on 21 December, but may vary by one day in either direction according to the Gregorian calendar. In the Northern Hemisphere, the December solstice is the winter solstice, whilst in the Southern Hemisphere it is the summer solstice.
A season is a division of the year based on changes in weather, ecology, and the number of daylight hours in a given region. On Earth, seasons are the result of the axial parallelism of Earth's tilted orbit around the Sun. In temperate and polar regions, the seasons are marked by changes in the intensity of sunlight that reaches the Earth's surface, variations of which may cause animals to undergo hibernation or to migrate, and plants to be dormant. Various cultures define the number and nature of seasons based on regional variations, and as such there are a number of both modern and historical cultures whose number of seasons varies.
The 2010–11 North American winter was influenced by an ongoing La Niña, seeing winter storms and very cold temperatures affect a large portion of the Continental United States, even as far south as the Texas Panhandle. Notable events included a major blizzard that struck the Northeastern United States in late December with up to 2 feet (24 in) of snowfall and a significant tornado outbreak on New Year's Eve in the Southern United States. By far the most notable event was a historic blizzard that impacted areas from Oklahoma to Michigan in early February. The blizzard broke numerous snowfall records, and was one of the few winter storms to rank as a Category 5 on the Regional Snowfall Index. In addition, Oklahoma set a statewide low temperature record in February.
The 2016–17 North American winter was quite warm across North America in general, due in part to a weak La Niña that was expected to influence weather conditions across the continent. Several notable events occurred during the season, including a potent winter storm that affected the East Coast of the United States in early January, the second-largest winter tornado outbreak on record later that month, and an unusually warm February. In addition, towards the end of the season, a large cyclonic storm system that caused a large tornado outbreak, flooding, and a potent blizzard occurred in the Heartland of the country. However, the most notable event of the winter was a powerful blizzard that impacted the Northeast and New England in mid-March, towards the end of the season.
Spring equinox or vernal equinox or variations may refer to:
The deepest snow is just north of Greenland and Ellesmere Island, peaking in early June at more than 40 cm