Japanese Calendar & Culture

Japan’s Four Seasons and the 24 Solar Terms: Discover the Traditional Japanese Calendar

Have you ever wondered why Japan is so closely associated with the changing seasons?

In spring, cherry blossoms turn parks and streets into a sea of pink. Summer brings lush green landscapes, colorful festivals, and fireworks lighting up the night sky. Autumn transforms mountains into brilliant shades of red and gold. And in winter, snowy scenery and quiet traditions create a completely different atmosphere.

But in Japan, the seasons are more than beautiful scenery.

For centuries, seasonal changes have influenced the way people farm, eat, celebrate, and organize their lives.

Behind many of these traditions is a fascinating concept known as the 24 Solar Terms, or Nijūshi Sekki (二十四節気).

This traditional calendar system divides the year into 24 seasonal markers, each reflecting a different stage in the annual journey of the sun.

Let's explore Japan's four seasons through the eyes of its traditional calendar.

What Are the 24 Solar Terms?

Imagine dividing the year not into 12 months, but into 24 smaller seasonal periods.

Instead of simply saying "It's spring," you might notice that the snow is beginning to melt, insects are waking from winter, or the first signs of autumn are appearing.

That is the basic idea behind the 24 Solar Terms.

The system originated in ancient China and was later adopted in Japan, where it became an important part of traditional calendar culture.

Today, each solar term is defined by the sun's apparent position along its annual path in the sky, at intervals of 15 degrees.

There are six solar terms in each of the four seasons.

Some names may already sound familiar, such as the spring equinox, summer solstice, autumn equinox, and winter solstice.

Others have wonderfully poetic meanings, including "Insects Awakening," "White Dew," and "First Frost."

But here's something that often surprises people.

According to this traditional calendar, spring begins in early February, and autumn begins in early August!

Why so early?

To understand that, we need to explore the Japanese way of seeing the seasons.

Spring in Japan: Cherry Blossoms and New Beginnings

Spring is perhaps Japan's most internationally famous season.

When people imagine spring in Japan, they often picture cherry blossoms, or sakura (桜), floating gently through the air.

Every year, people gather under blooming cherry trees for hanami (花見), the tradition of enjoying the blossoms.

Friends, families, and coworkers spread picnic blankets beneath the trees, sharing food and conversation while admiring the flowers.

Because cherry blossoms bloom for only a short time, they are often associated with the beauty and fleeting nature of life.

Yet according to the traditional calendar, spring begins long before the cherry blossoms appear.

Risshun (立春): The Beginning of Spring

Risshun, usually occurring around February 4, marks the beginning of spring in the 24 Solar Terms.

In much of Japan, February is still freezing cold. Snow may cover the mountains, and people are wrapped in winter coats.

So why is it called spring?

Because the traditional calendar describes the progression of the sun through the year, rather than the weather on one particular day.

Risshun represents a turning point: the season is beginning its journey toward spring, even if winter still feels very much alive.

The day before Risshun is traditionally known as Setsubun (節分).

One popular Setsubun custom is mamemaki, or bean throwing.

People throw roasted soybeans while calling out:

"Oni wa soto! Fuku wa uchi!"

"Demons out! Good fortune in!"

The practice symbolizes driving away misfortune and welcoming good fortune as a new season approaches.

Setsubun is not one of the 24 Solar Terms itself, but it is closely connected to the seasonal boundary marked by Risshun.

Keichitsu (啓蟄): When Insects Awaken

Around March 5 comes Keichitsu, often translated as "Insects Awakening."

The name describes the time when creatures that have been hidden underground during winter begin to emerge.

It's a charming reminder that the arrival of spring is not just about flowers.

The natural world is slowly becoming active again.

By late March or April, cherry blossoms may begin to bloom in many parts of Japan.

Their timing varies considerably by region, with blossoms generally appearing earlier in warmer areas and later in colder northern regions.

The traditional solar terms do not predict the exact day of the cherry blossoms. Instead, they provide a broader framework for understanding the changing season.

The Six Solar Terms of Spring

Risshun (立春) — Beginning of Spring
Usui (雨水) — Rain Water
Keichitsu (啓蟄) — Insects Awakening
Shunbun (春分) — Spring Equinox
Seimei (清明) — Clear and Bright
Kokū (穀雨) — Grain Rain

Together, these six names describe the gradual transition from winter's cold to the warmth and growth of spring.

Summer in Japan: Rain, Greenery, and Festivals

Summer in Japan is a season full of energy.

The countryside turns a deep green as rice fields grow. Cicadas fill the air with their distinctive calls. Summer festivals bring communities together with traditional dances, food stalls, and fireworks.

But before the hottest days arrive, much of Japan experiences tsuyu (梅雨), the rainy season.

The rainy season generally occurs from late spring into early summer, although its timing and character differ by region.

Rain is an important part of Japan's seasonal environment, particularly for rice cultivation.

And this connection between weather, agriculture, and daily life is reflected in the traditional calendar.

Bōshu (芒種): The Season of Grain

Around June 6 comes Bōshu, a solar term associated with grains such as rice and wheat.

Its traditional meaning relates to the cultivation of grain crops, reflecting the agricultural knowledge that shaped the calendar.

In Japan, this period is closely associated with the early summer growing season.

However, agricultural schedules differ by region, climate, and farming practice. The solar term is a seasonal marker, not a fixed planting date for every farmer.

Geshi (夏至): The Summer Solstice

Around June 21 comes Geshi, the summer solstice.

In the Northern Hemisphere, this is the time of year when daylight lasts the longest.

Here's something interesting.

Although the summer solstice has the longest day, it usually isn't the hottest day of the year.

In much of Japan, the most intense summer heat arrives later, during July and August.

The traditional calendar recognizes this progression.

Shōsho (小暑), or "Minor Heat," arrives in early July, followed by Taisho (大暑), or "Major Heat," later in the month.

As temperatures rise, people enjoy seasonal foods, attend local festivals, and celebrate summer evenings with fireworks.

The festivals themselves do not all originate from the 24 Solar Terms, but both reflect Japan's long connection between the seasons and cultural traditions.

The Six Solar Terms of Summer

Rikka (立夏) — Beginning of Summer
Shōman (小満) — Lesser Fullness
Bōshu (芒種) — Grain in Ear
Geshi (夏至) — Summer Solstice
Shōsho (小暑) — Minor Heat
Taisho (大暑) — Major Heat

These names follow the growing warmth of early summer toward the height of the season.

Autumn in Japan: Red Leaves, Harvests, and Gratitude

Autumn brings one of Japan's most breathtaking transformations.

Mountains, gardens, and temple grounds become covered in red, orange, and golden leaves.

The tradition of enjoying autumn foliage is called momijigari (紅葉狩り), often translated as "autumn leaf viewing."

Just as people gather to admire cherry blossoms in spring, many travel to parks, forests, and mountains to enjoy the autumn colors.

Autumn is also associated with harvests, seasonal foods, and a sense of gratitude for nature's abundance.

But here's another surprise.

According to the traditional calendar, autumn begins around August 7, when much of Japan is still experiencing intense summer heat.

Risshū (立秋): The Beginning of Autumn

Risshū marks the traditional beginning of autumn.

Although the weather may still feel like midsummer, the sun has reached another important point in its annual journey.

The days are gradually becoming shorter.

This is one reason the traditional calendar can seem ahead of the weather.

It follows astronomical changes rather than waiting for the air to become cool.

Hakuro (白露): White Dew

Around September 7 or 8 comes Hakuro, meaning "White Dew."

The name evokes the delicate droplets of dew that begin appearing on grasses and leaves as the air cools.

It's a beautiful example of the poetic language found in Japan's traditional seasonal calendar.

Instead of describing a season only as hot or cold, the solar terms invite us to notice small changes in nature.

Shūbun (秋分): The Autumn Equinox

Around September 22 or 23 comes Shūbun, the autumn equinox.

Day and night are approximately equal in length around this time.

In Japan, the equinox is also associated with Higan (彼岸), a Buddhist observance connected with remembering ancestors.

During the seven-day Higan period centered on the equinox, many families visit graves, clean memorial sites, and offer prayers.

This tradition shows how astronomical seasonal markers became connected with religious and family customs.

As autumn deepens, the solar terms progress toward Kanro (寒露), or "Cold Dew," and Sōkō (霜降), often translated as "First Frost."

The names suggest the approaching chill of winter.

The Six Solar Terms of Autumn

Risshū (立秋) — Beginning of Autumn
Shosho (処暑) — Heat Subsides
Hakuro (白露) — White Dew
Shūbun (秋分) — Autumn Equinox
Kanro (寒露) — Cold Dew
Sōkō (霜降) — First Frost

These terms describe the gradual transition from late-summer heat to the coolness of autumn.

Winter in Japan: Snow, Warm Traditions, and the Return of Light

Winter offers another remarkable side of Japan.

In northern regions and mountainous areas, deep snow transforms the landscape.

Traditional wooden houses and temple roofs appear beneath blankets of white, while hot springs offer a welcome escape from the cold.

But winter is not the same everywhere in Japan.

Hokkaido may experience heavy snow, while parts of Okinawa remain relatively mild.

The country's great geographical diversity is an important reminder that seasonal traditions and actual weather do not always match perfectly.

Rittō (立冬): The Beginning of Winter

Rittō, usually around November 7, marks the beginning of winter in the traditional calendar.

Autumn leaves may still be colorful in many regions, but the sun has already entered the next phase of its annual cycle.

Tōji (冬至): The Winter Solstice

Around December 21 or 22 comes Tōji, the winter solstice.

This is the time of year when the Northern Hemisphere experiences its shortest period of daylight.

After the winter solstice, daylight gradually begins to increase again.

In Japan, Tōji has become associated with some distinctive seasonal customs.

One is eating kabocha, a type of Japanese pumpkin or winter squash.

Traditionally, eating kabocha on the winter solstice has been associated with hopes for good health during the cold months.

Another is taking a yuzuyu (柚子湯), a warm bath scented with yuzu citrus fruit.

The fragrance of yuzu creates a comforting winter atmosphere, and the bath has long been connected with seasonal well-being customs.

These traditions do not mean that pumpkin or yuzu can guarantee good health.

They are cultural practices that express people's wishes to stay healthy and welcome the return of longer days.

Shōkan and Daikan: The Depth of Winter

In January come Shōkan (小寒), or "Minor Cold," and Daikan (大寒), or "Major Cold."

These terms mark the deepening cold of winter.

Yet by this point, the days are already getting longer.

Even during the coldest part of the year, the cycle is slowly moving toward spring.

The Six Solar Terms of Winter

Rittō (立冬) — Beginning of Winter
Shōsetsu (小雪) — Minor Snow
Taisetsu (大雪) — Major Snow
Tōji (冬至) — Winter Solstice
Shōkan (小寒) — Minor Cold
Daikan (大寒) — Major Cold

After Daikan, the cycle returns once again to Risshun, the beginning of spring.

Why Doesn't Japan's Traditional Calendar Match the Weather?

You may have noticed that the seasonal calendar often seems different from what people actually experience.

Spring begins in February, even when snow is falling.

Autumn begins in August, when the summer heat is still intense.

There are two important reasons.

First, the 24 Solar Terms are based on the sun's position, not local temperatures.

Second, the system originated in ancient China, where its seasonal expressions developed in a different geographical and historical environment.

Japan later adopted and adapted this system into its own calendar traditions.

The climate also differs considerably across Japan, from snowy Hokkaido in the north to subtropical Okinawa in the south.

So the 24 Solar Terms should not be understood as an exact weather forecast.

They are astronomical seasonal markers accompanied by traditional observations and cultural meanings.

Knowing this makes the calendar more interesting, not less.

It reminds us that there are different ways to experience the same season.

How the Traditional Calendar Connected the Moon and the Sun

Before Japan adopted the modern Gregorian calendar in 1873, it used a lunisolar calendar.

A lunisolar calendar combines the cycles of the moon with the movement of the sun.

The lunar months follow the phases of the moon, but 12 lunar months add up to only about 354 days.

That is roughly 11 days shorter than the solar year.

Without adjustments, the calendar months would gradually drift away from the seasons.

The 24 Solar Terms helped solve this problem.

They provided a solar framework for determining the traditional months and when an additional leap month was needed.

In this way, the traditional Japanese calendar brought together two celestial rhythms: the changing moon and the annual journey of the sun.

The calendar was not merely a collection of dates.

It was also a way of understanding how time, nature, and human activities fit together.

A Different Way to Experience Japan's Four Seasons

Today, most people use calendars to remember appointments, holidays, and deadlines.

But what if a calendar could also remind us to notice the natural world?

The first sign of spring.

The smell of rain before summer.

The appearance of dew on a cool autumn morning.

The gradual return of daylight after the winter solstice.

Japan's traditional seasonal calendar encourages us to pay attention to these quieter changes.

You don't have to live in Japan to appreciate that idea.

Wherever you are in the world, the seasons offer small changes worth noticing.

Of course, the timing and experience of those seasons may be very different depending on where you live.

But the idea of connecting human life with the rhythms of nature is something many cultures share.

Discover Another Side of the Japanese Calendar with Tenchi Koyomi

The 24 Solar Terms are one fascinating part of Japan's traditional calendar culture.

But the old Japanese almanac had another purpose as well.

Alongside seasonal information, traditional calendars included notes about particular days and activities.

These notes reflected the custom of considering when certain activities might be suitable or better avoided.

Tenchi Koyomi explores these traditional calendar ideas through a modern perspective.

Rather than predicting the future, it offers a different way to think about the timing of everyday activities, drawing on traditional calendar concepts and its own contemporary interpretations.

The calendar uses Japan Standard Time (JST), and its activity-specific results are interpretations, not guarantees of outcomes.

Perhaps the next time you look at a calendar, you'll see more than a date.

You might discover an entirely different way of thinking about time.

Explore today's Tenchi Koyomi calendar (currently in Japanese)