Japan’s Seasonal Calendar: 24 Solar Terms & 72 Microseasons

Japan’s 24 solar terms, or sekki, divide the solar year into smaller seasonal markers. The 72 kō divide each term into three observations of nature. They are a useful way to notice a trip’s small details: a sweet shaped like a leaf, a display of new rice, or a calendar naming an insect you have never thought to look for.

They do not replace spring, summer, autumn and winter, and they cannot tell you when a particular tree will flower. The interesting contrast is between an orderly calendar and the much less orderly world outside.

This guide gives the 2026 start dates of all 24 terms, explains some of the stranger microseason names, and shows how to use the idea without mistaking it for a weather forecast. It is based on the astronomical observatory, library and confectioner sources below; it is not a report of a tasting tour.

Two different kinds of seasonal precision

The National Diet Library’s calendar guide explains the 24 terms as six divisions within each of the four seasons. Their names can sound like weather reports: “white dew,” “greater heat,” “light snow.” Their modern dates, however, are determined by the Sun’s position, not by a thermometer in Tokyo.

That gives you a dependable calendar marker, without a dependable promise of matching weather. Risshū, the beginning of autumn, can arrive while a city is still very hot. Risshun, the beginning of spring, does not mean a mountain trail is snow-free.

The National Astronomical Observatory’s explanation of the 72 kō adds an important limit: the nature observations do not identify exact days, and some preserve pre-scientific ideas. Names and readings also vary between calendars. “About five days” is a helpful introduction, not evidence that every shop follows a fixed five-day programme.

The 24 solar terms: 2026 start dates

Dates below are Japanese calendar dates, taken from NAOJ’s 2026 calendar. The English meanings are short reading aids. Use the latest start date at or before your travel date to identify its term; the next row marks the next transition.

2026 start	Solar term	Meaning
January 5	Shōkan 小寒	Lesser cold
January 20	Daikan 大寒	Greater cold
February 4	Risshun 立春	Beginning of spring
February 19	Usui 雨水	Rainwater
March 5	Keichitsu 啓蟄	Insects awaken
March 20	Shunbun 春分	Spring equinox
April 5	Seimei 清明	Clear and bright
April 20	Kokuu 穀雨	Grain rain
May 5	Rikka 立夏	Beginning of summer
May 21	Shōman 小満	Small fullness
June 6	Bōshu 芒種	Grain in ear
June 21	Geshi 夏至	Summer solstice
July 7	Shōsho 小暑	Lesser heat
July 23	Taisho 大暑	Greater heat
August 7	Risshū 立秋	Beginning of autumn
August 23	Shosho 処暑	Heat recedes
September 7	Hakuro 白露	White dew
September 23	Shūbun 秋分	Autumn equinox
October 8	Kanro 寒露	Cold dew
October 23	Sōkō 霜降	Frost descends
November 7	Rittō 立冬	Beginning of winter
November 22	Shōsetsu 小雪	Light snow
December 7	Taisetsu 大雪	Heavy snow
December 22	Tōji 冬至	Winter solstice

Start dates can shift between years. For a January trip, use that year’s table rather than assuming that the previous December row supplies the whole winter. This table is not a list of public holidays, festival dates, opening hours or flowering observations.

The microseasons are stranger than the solar terms

The calendar tradition came from China and was adapted in Japan. NAOJ records revisions by Shibukawa Shunkai, followed by further changes in the Hōreki calendar. The present names are not simply an unchanged notebook from one person in 1685.

A few examples from NAOJ’s later-calendar column show why the idea has such appeal:

Term	Microseason	A plain-English reading
Risshun	東風解凍 — Harukaze kōri o toku	The east wind melts the ice
Shunbun	桜始開 — Sakura hajimete hiraku	Cherry blossoms begin to open
Kokuu	牡丹華 — Botan hana saku	Peonies bloom
Bōshu	腐草為蛍 — Kusaretaru kusa hotaru to naru	Decaying grass becomes fireflies
Hakuro	玄鳥去 — Tsubame saru	Swallows depart
Sōkō	楓蔦黄 — Momiji tsuta kibamu	Maple and ivy turn yellow

The firefly name is especially memorable because it preserves an old explanation of nature rather than modern biology. Read it as cultural history. It does not mean grass produces insects, or that a firefly tour can guarantee sightings in that interval.

This is also why we give the containing term, rather than presenting a single set of five-day boundaries as an official nationwide nature timetable. A calendar’s label, a local observation and a visitor attraction’s event schedule answer different questions.

An actual way to try the idea: seasonal wagashi

A fresh sweet is a manageable way to explore the calendar without planning a cross-country chase. Look at its name, colour and form, then ask what the design refers to. A leaf-shaped sweet and a real leaf outside need not be at exactly the same stage to make the comparison interesting.

Toraya describes its seasonal fresh sweets as changing about every half-month. It also limits their sale to selected outlets and notes regional differences. That is a concrete example of a producer reflecting seasonal change; it does not establish that all wagashi shops change every five days or sell one designated sweet for each kō.

For a visit:

1. Choose a shop already near your route and open its current menu.
2. Check the outlet and sale dates for the particular sweet. A brand’s online catalogue does not mean every counter stocks it.
3. Ask “Ima no kisetsu no okashi wa dore desu ka?” — “Which sweets are seasonal now?” You do not need to memorise a microseason name.
4. Check ingredients if you have dietary restrictions, and follow the shop’s storage and eating guidance.

That produces a small, specific encounter with seasonality without claiming a tasting result in advance. Our wagashi and microseasons explainer explores the naming tradition further.

Turn the calendar into a better itinerary

Use the terms to choose questions, then use operators’ current information to choose activities.

If the calendar makes you curious about…	Check before making a special journey
Blossom or autumn-leaf names	Current observations for the actual park and elevation
A seasonal sweet	That shop’s menu, outlet, sale period and stock
A solstice bath	The bathhouse’s own event notice and normal admission rules
A shrine or garden event	The organiser’s dated announcement, access and ticket conditions

For example, November 5–12, 2026 crosses from Sōkō into Rittō on November 7. That is a calendar transition, not a reason to move hotels that day. Pick a destination and nearby alternatives, then use the current autumn-leaf forecast guide and the garden’s own updates to decide where to go.

A two-week trip does not automatically contain three solar terms; starts are roughly fifteen days apart. Crossing regions also does not move the astronomical calendar backward. Different regions can have different weather and foliage on the same calendar date.

Likewise, the calendar alone cannot make a rail pass good value. Decide the journeys first and compare ticket costs using our JR Pass planning guide. There is no need to add an expensive rail journey to experience a different seasonal sweet.

What to notice when you arrive

Save the term for your arrival date. Choose one local place you already wanted to visit: a garden, a food counter, a neighbourhood bath. Look for one detail that makes sense of the name, and one that does not.

The difference is part of the story. “Beginning of winter” on a warm afternoon is not a failed holiday. It is a reminder that Japan has several ways to describe the year, and that a traditional calendar is one way of paying attention rather than an instruction for what nature must do.

For the practical part of a seasonal bath visit, use the Tokyo sento guide and first-time onsen guide. Check the chosen operator’s dated announcement before treating a seasonal custom as a scheduled event.