47 Fun Facts About Seasons

What is the primary cause of Earth's seasons?

The tilt of the planet's axis is the cause: each hemisphere leans toward the Sun for half the orbit, getting more direct sunlight and longer days, then leans away.

By roughly how much is Earth's axis tilted relative to its orbital plane?

Earth's obliquity is about 23.4°; it wobbles between 22.1° and 24.5° over a 41,000-year cycle, one of the Milankovitch cycles that pace ice ages.

In which month is Earth closest to the Sun?

Perihelion, Earth's closest approach, falls in early January, around the 3rd or 4th, while aphelion comes in early July, so distance works against the Northern Hemisphere's seasons.

Why is Earth as a whole slightly warmer when it is farthest from the Sun?

Aphelion falls during the northern warm season, and the Northern Hemisphere has more land, which warms faster than sea, so Earth's mean temperature peaks in July despite the extra distance.

The word 'solstice' comes from Latin words meaning what?

Solstice joins Latin sol, 'sun', and sistere, 'to stand still': at the solstices the Sun's daily path reaches its northern or southern limit and seems to pause before reversing.

'Equinox' comes from Latin words meaning what?

Equinox comes from Latin aequus, 'equal', and nox, 'night': at the two equinoxes the Sun stands overhead at the Equator and day and night are nearly equal everywhere.

Around what date does the Northern Hemisphere tip most toward the Sun?

Around June 21 the Northern Hemisphere tips most toward the Sun: the June solstice, the longest day north of the Equator; the Southern Hemisphere's turn comes around December 21.

Why are July and August, not June, usually the hottest months in the Northern Hemisphere?

Seasonal lag is the cause: sunlight peaks at the solstice, but oceans absorb and release heat slowly, so air temperatures crest weeks later in July and August.

Under meteorological reckoning, on what date does spring begin in the Northern Hemisphere?

Meteorological spring starts March 1: meteorologists split the year into three-month blocks beginning March 1, June 1, September 1 and December 1 for tidy record-keeping.

On the traditional Celtic calendar, which festival on November 1 marked the start of the coldest season?

Imbolc opened spring on February 1, Beltane summer on May 1 and Lughnasadh autumn on August 1. Samhain is the Celtic root of Halloween.

How many seasons, or ritus, does the traditional Hindu calendar recognize?

They are Vasanta, Grishma, Varsha (monsoon), Sharada, Hemanta and Shishira. Some Aboriginal Australian peoples and the Sami count up to eight.

The ancient Egyptian year had three seasons defined by what?

They were flood, growth and low water. Many tropical regions today still count just two seasons, wet and dry.

Which of these names a season in the ecological calendar used for temperate regions?

Prevernal, vernal, estival, serotinal, autumnal and hibernal make up the ecological model, keyed to biological events such as budding and leaf fall rather than calendar dates.

Before the 16th century, what word was commonly used in English for the season we now call autumn?

Harvest was the usual English word for the season until the 16th century, a cognate of Dutch herfst and German Herbst; 'fall' later caught on in North American English.

The yellow and orange colors of autumn leaves come from which pigments?

Carotenoids such as xanthophylls and beta-carotene sit in the leaf all through the growing season, masked by chlorophyll's green, and show through as yellow and orange once chlorophyll breaks down.

Which pigment gives autumn leaves their red color?

Anthocyanin gives leaves their red: unlike the yellows, it is made fresh in autumn from sugars trapped in the leaf, while browns come from tannins.

Which full moon is the one farmers traditionally named for bringing in the crops?

This full moon is the one nearest the autumnal equinox, so it can fall up to about two weeks either side of September 22 or 23 and occasionally lands in October.

What is an 'Indian summer'?

An Indian summer is a warm, dry spell in autumn after the first frost; the term was first recorded in North America in the 1770s and its origin is uncertain.

The 'dog days' of summer were named for the rising of which star?

Sirius, the Dog Star, rises with the Sun in the hottest weeks of the year; Hellenistic astrology blamed that rising for heat, drought, lethargy and mad dogs. The Greek Seirios means 'scorcher'.

On what date is Groundhog Day observed?

Groundhog Day falls on February 2, the old feast of Candlemas; Punxsutawney Phil has delivered his forecast at Gobbler's Knob since 1887.

In the German tradition before Groundhog Day, which animal's Candlemas shadow predicted four more weeks of cold?

In German lore a badger (Dachs) emerging into sunshine at Candlemas foretold more weeks of cold; Pennsylvania German settlers swapped in the groundhog and stretched the forecast by a further fortnight.

Midsummer celebrations were Christianized as the June 24 feast of which biblical figure?

The feast is the Nativity of John the Baptist, placed half a year before Christmas; Sweden takes Midsummer so seriously that there have been proposals to make it the national day.

In Greek myth, Hades tricked Persephone into eating what, binding her to the underworld?

Persephone ate pomegranate seeds in the underworld, so she must spend part of each year with Hades; Demeter's grief during those months was the myth's explanation for the cold, barren part of the year.

Stonehenge is aligned toward the sunrise on which day?

Stonehenge's main axis points to sunrise on the summer solstice, when the Sun rises over the Heel Stone; the same axis frames sunset on the December solstice.

Each concerto in Vivaldi's Four Seasons is paired with what kind of poem?

Each concerto is paired with a sonnet whose lines are keyed to passages in the score; the three movements match three sections of each poem, and Vivaldi himself may have written them.

In what year were Vivaldi's Four Seasons published?

The Four Seasons were published in Amsterdam in 1725 as the opening concertos of Vivaldi's Op. 8, Il cimento dell'armonia e dell'inventione (The Contest Between Harmony and Invention).

Frankie Valli's group The Four Seasons took its name from what?

The group took its name from the Four Seasons bowling alley in Union, New Jersey, after failing a 1960 audition to play its cocktail lounge.

Which of these was a number one single for The Four Seasons?

'Sherry', written by Bob Gaudio, topped the Hot 100 in 1962 and was followed to number one by 'Big Girls Don't Cry', 'Walk Like a Man' and 'Rag Doll'.

Haydn's oratorio The Seasons, first performed in 1801, is based on a long English poem by whom?

Thomson's The Seasons was published in 1730. Baron van Swieten adapted it so freely that scholars say the libretto often loses touch with the poem.

On Uranus, tilted almost 98 degrees, roughly how long does each pole spend in continuous sunlight?

Its orbit takes 84 Earth years, so each pole gets about 42 years of daylight followed by 42 years of dark, the most extreme seasons in the solar system.

The midnight sun occurs in summer beyond which lines of latitude?

Because of refraction it can be seen from about 65 degrees 44 minutes, slightly outside the Arctic and Antarctic circles.

What is the Japanese custom of viewing cherry blossoms in spring called?

Hanami, literally 'flower viewing', is the custom of picnicking under cherry blossoms; the bloom sweeps Japan from late March to early May, starting far earlier in Okinawa.

How much does the amount of sunlight Earth receives vary between perihelion and aphelion?

Sunlight at perihelion is about 7 percent stronger than at aphelion, a swing swamped by axial tilt and partly offset by the Southern Hemisphere's abundance of ocean.

Which people of Scandinavia traditionally recognize up to eight seasons?

The Sami calendar follows reindeer herding through eight seasons, slotting transitional periods between the usual ones, each tied to a stage of the reindeer year such as calving or the autumn rut.

How much earlier do Celtic cross-quarter seasons start than equinox-and-solstice seasons?

Cross-quarter seasons begin on February 1, May 1, August 1 and November 1, about 6 to 7 weeks before the equinoxes and solstices, which they treat as midpoints rather than beginnings.

Earth's axis keeps pointing toward which star all year, a property called axial parallelism?

The axis points toward Polaris, the North Star, throughout the orbit; it does wobble, but so slowly that the drift is invisible within a human lifetime.

Roughly how long is Earth's axial precession cycle?

Axial precession takes about 26,000 years: the axis traces a slow circle, so in roughly 12,000 years the bright star Vega will sit near the celestial pole.

Which season is defined as the coldest and darkest of the year in temperate and polar climates?

Winter is the coldest, darkest season: around the December solstice in the north the Sun stays lowest in the sky, and at high latitudes it may not rise at all.

At the spring equinox, roughly how long are day and night?

At the equinox day and night are each roughly twelve hours long everywhere on Earth; the astronomical vernal equinox falls between March 19 and 21.

Which astronomer showed that the astronomical seasons are unequal in length because Earth's orbit is an ellipse?

March equinox to September equinox currently runs 7.56 days longer than the other half of the year.

How many climatological seasons does the India Meteorological Department designate?

The IMD designates four seasons: a cool season in the first two months of the year, the pre-monsoon hot season, the southwest monsoon from June to September, and the post-monsoon period that follows.

The traditional Chinese calendar divides its four seasons into how many 'solar terms'?

The year is split into 24 solar terms of about 15 days each, alternating jiéqì and zhōngqì; spring begins at Lìchūn, around February 4.

In Nicaragua, the dry season from November to April is popularly called what?

Nicaraguans call the November-to-April dry season 'summer' (verano) and the rainy months invierno, even though the country lies north of the equator.

On which planet does each season last roughly seven Earth years?

Saturn takes about 29.5 Earth years to orbit the Sun and is tilted about 27 degrees, so each of its seasons lasts roughly seven Earth years.

In Sweden and Finland's thermal seasons, spring begins when the mean daily temperature permanently rises above what?

Summer starts above +10 °C and winter below 0 °C; Finland defines 'permanently' as seven consecutive days.

Who was the Roman god of the seasons?

Vertumnus was the Roman god of seasons, change and plant growth, able to shift his form with the turning year; Ovid tells of his courtship of Pomona.

Which 1780 body first defined meteorological seasons as groupings of three whole calendar months?

The Societas Meteorologica Palatina, an international weather-observing network based in Mannheim from 1780 until 1795, fixed each season as three whole calendar months, the convention meteorologists have followed ever since.