The science of springtime, 101

Dive into the basics on springtime including the astronomy that brings it about, natural signs of spring's arrival, and some of the cultural approaches to the season.

Meteorological v. astronomical seasons, explained

Meteorologists and climatologists define seasons differently from “regular” or astronomical spring, summer, fall, and winter. Traditional seasons reflect the movement of celestial objects, known as the astronomical seasons; meteorologists mark seasonal change based on temperature averages.

Twelve ways the world celebrates springtime

Celebrating the seasonal change is rarely filled with as much relief and hope around the world as spring. This list compiles some famous and lesser-known springtime traditions from diverse cultures.

Why we have different seasons

Visualize just how exactly seasons come to be with this animation of the earth in relation to the sun, and see how earth's tilt determines our seasons.

The Aztecs synced their solar calendar with a complex 260-day ritual cycle

Researchers have uncovered how the Aztecs aligned their agricultural solar calendar with a symbolic 260-day ritual calendar, utilizing celestial tracking and monuments. Evidence from ruins and writings explains why their new year corresponded to February 23 on the Gregorian calendar.

The solstice has been celebrated globally for millennia.

Grasp the earth's orbit around the sun with this interactive

See why seasons exist with this interactive simulator. Toggle between different views of the earth in relation to the sun and watch as the earth's axis causes the sun to shine at different angles throughout the year, causing the weather to fluctuate and more. This simulator clarifies a process many take for granted.

The winter solstice has been celebrated globally for millennia

From gatherings at Stonehenge in the UK to celebrations of the triumph of Mithra in Iran, cultures around the world have marked the shortest day of the year in a variety of ways for a very long time. Here are eight known to us today that endure.

How lunisolar calendars work

Despite being called Lunar New Year, the Chinese calendar that the holiday is based on is actually lunisolar, or based on both the sun and the moon. Many religious holidays—including Easter, Ramadan, Chinese New Year, and Passover—do not have fixed dates according to the now-ubiquitous Gregorian calendar.

A medieval warm period reshaped agriculture across parts of the world

Between 750 and 1350 CE, some regions experienced temperatures that rivaled or exceeded late-20th-century averages, likely due to shifts in El Niño–La Niña cycles. The warmer, wetter climate in Europe and northeast North America boosted agriculture, while causing droughts elsewhere.

How the months of the year got named

Curious about how the months got their names? This article from The Old Farmer's Almanac explores the origins of today’s Gregorian calendar. Based on the ancient Roman lunar calendar, the months were named after Roman gods until winter when the names changed to numerical titles. Read along to learn the significance and intentions behind labeling each lunar cycle.

China has used several different calendars because of changes in government structure

For many centuries, during which China was an imperial nation, the lunar/lunisolar calendar (aka the “rural calendar”) was the basis for organizing the year. Several attempts were made over the decades to switch to the Gregorian calendar—which begins Jan. 1—but it wasn’t until the People’s Republic of China was founded in 1949 that it stuck.

Lunar New Year is celebrated around the globe

“Lunar New Year” is a catchall term that encompasses celebrations in several Asian countries. The date of the new year can vary by location depending on which calendar—lunar, lunisolar, or solar—is being used, but many of the traditions are shared across borders.

New Year's Eve celebrations date back to ancient Babylon

Rather than celebrating in winter, the Babylonians honored the vernal equinox, a day in late March with equal amounts of darkness and light that signaled the start of a new year. They celebrated with Akitu, an 11-day festival.

Changes in Earth's orbital cycles influence the timing of ice ages

These cycles include changes in Earth's orbit shape, tilt, and wobble, all of which alter how much solar energy different parts of Earth receive over time. Due to orbital eccentricity, summers in the Northern Hemisphere last about 4.5 days longer than winters.

The Ancient Chinese harnessed solar power for heating and cooling 6,000 years ago

Neolithic Chinese homes faced south for winter sun warmth, while overhangs shielded them from high summer sun. These efforts also influenced urban planning, with cities aligning streets east-west for optimal solar exposure.

The world's different calendars, explained

The calendar we use to mark the days, months, and year can feel set in stone, but the history of calendars shows these organization systems can and do change. Parse the fascinating, complex details of the Gregorian, Julian, Chinese, Hebrew, and many more calendars in this comprehensive, well-executed explainer video.

The era of advanced farming machines

Traditional agriculture, which for millennia was conducted primarily as subsistence farming by millions of workers, has been transformed since the industrial revolution. Agribusinesses continue to develop newer, more specific tools to streamline the...

The science of spring fever

Researchers have confirmed what people have sensed for ages: Our emotions during the springtime can go a little wild. This piece breaks down the impact of the seasonal transition on our bodies and prescribes a few ways to mitigate the effects.

Why meteorologists say summer starts June 1

There are at least two periods called summer: astronomical and meteorological. Astronomical summer mirrors the movement of celestial bodies and begins roughly around June 20, with the summer solstice. Meteorologists designate the beginning of June as the start of summer to make tracking weather patterns from year to year easier.

Five things to know about autumnal equinoxes

After the autumnal equinox, the northern hemisphere of the Earth begins to tilt away from the sun, so nights will get longer and days grow shorter.

Every eclipse is preceded or followed by another eclipse, separated by about two weeks and alternating between solar and lunar types.

The Hungry Ghost Festival in Asia honors the dead

A tradition in East and Southeast Asia, the Hungry Ghost Festival primarily involves offering food and other treats to the dead. The festivals' practices uphold the Buddhist ideals of generosity and compassion, directed even toward specters.

See how Advent traditions vary widely around the world

Advent is celebrated in distinct ways across countries—Chinese Christians hang colorful lanterns, Mexicans reenact Las Posadas processions, Germans light weekly wreath candles, and Hungarians attend dawn matins—reflecting how local cultures shape the season’s preparation.

Early European observance varied between penitential and celebratory seasons

For centuries, churches disagreed over the purpose of Advent: Gaul and Spain treated it as a long, penitential fast beginning on November 11, while Rome observed a shorter, more joyful season. These competing traditions were only blended into a unified Advent in the Middle Ages.

East Asian records of auroras may date back to 10,000 BCE

Ancient texts from Japan, Babylon, and China contain accounts of auroras dating back millennia. Because auroral activity and intensity are driven by periodic ebbs and flows in solar activity, these records allow scientists to identify patterns that may help anticipate particularly dangerous future solar storms.

How people imagine a calendar year

It turns out everybody imagines the abstract calendar year in a simple, concrete way, though there are surprising differences between the exact model and shape of each image. Dive into one writer's collection of tens of thousands of questionnaire responses showing the fascinating consistency and divergence of how people visualize time.

The Köppen-Geiger system divides Earth’s climate into five main categories

This classification system, developed by a German-Russian botanist and a German climatologist, results from differences in the intensity of solar radiation and rainfall in different parts of the world. Each category is further divided into multiple coded zones.

Some Christian communities start Advent six weeks before Christmas instead of four

While most Western churches begin Advent on the fourth Sunday before Christmas, the Ambrosian Rite (northern Italy) and the Mozarabic Rite (Spain) begin six Sundays before Christmas.

A vegetarian diet is part of the Lunar New Year tradition

In keeping with China’s long history of Buddhism, which encourages vegetarianism, particularly on the first and 15th day of the lunar month, many people eat a plant-based diet (or at least a plant-based meal) on the first day of the Lunar New Year. The custom is supposed to increase participants’ good karma, bringing them extra blessings for the year to come.

Monsoons are large, seasonal shifts in wind direction driven by differences in the heating of land and sea.

The Archaic period marked Native Americans' shift from big-game hunting to foraging

Beginning around 8000 B.C.E., Indigenous peoples began relying on diverse food sources—including wild game, plants, seeds, and fish—and moved away from large-mammal hunting. Archaeological findings from this era suggest some communities began cultivating crops and establishing irrigation systems, indicating a shift toward less-nomadic lifestyles.

The common 'Three Sisters' mound-planting system used by natives

In the 17th century, Native Americans cultivated a three-plant combination of corn, beans, and squash—a symbiotic tradition dating back hundreds of years. The corn allowed the beans to climb, the beans fertilized the plants by extracting nitrogen from the air, and the squash leaves protected the soil and preserved moisture. Learn more about the tradition here.

The Lunar New Year lasts 15 days, with specific rituals for specific days

On the first night, loved ones gather to celebrate their honor and say goodbye to the successes and tribulations of the old year. On the fourth day, the God of the Kitchen is honored to prevent kitchen accidents. And beginning on day 12, people prepare for the final Festival of Lanterns.

Explained: The Year of the Rabbit

One of the world's largest holidays, this visual guide will help you welcome the Year of the Rabbit and celebrate the new lunar year.

Emulating Earth’s light-dark cycle is important for astronaut health and safety

Astronauts aboard the International Space Station experience 16 daily sunrises, but scientists have learned to try to promote circadian rhythms by phasing through several light settings aboard the ISS to improve astronauts’ sleep and productivity.

This year's first leaf and first bloom in the US, mapped

Spring tends to arrive within a range of dates in the contiguous US. See a map illustrating the most recent year's first leaf and first bloom in relation to historical averages to see how early or late the season arrived.

The ancient crops we've forgotten how to grow

Roughly half of all world calories today stem from maize, wheat, and rice. But for most of history, plants were domesticated in highly local places. This video dives into the scientists learning about crops no longer highly in use that once fueled entire civilizations in North America. Some forgotten crops include pitseed goosefoot, maygrass, and sumpweed.

Why do people play farming simulation video games?

This article is an anthropological dive into farming simulation video games. Humans began experimenting with agriculture and farming about 12,000 years ago, though it would be another 8,000 years before the practice became a common approach across...