The core idea: one sample tree decides the date
At each observation point, the Japan Meteorological Agency, Kishōchō (気象庁), has chosen one hyōhon-boku (標本木), literally a specimen tree, usually a Somei Yoshino, the pale cherry planted in parks all over Japan. Tokyo's stands in the grounds of Yasukuni Shrine. Staff watch that one tree. When five or six flowers are open, the city has its kaika (開花), literally opening of flowers. When about 80 percent of the buds are open, it has mankai (満開), literally full opening.
Everything else follows from this. The date is a fact about one tree, not about every tree in the city: a sunny slope may bloom days earlier, a shaded street later. Here is how television news reports the day.
| Japanese | Romaji | Meaning |
|---|---|---|
| 東京で桜の開花が発表されました。 | Tōkyō de sakura no kaika ga happyō saremashita. | Cherry blossoms have officially opened in Tokyo. |
| 標本木で五、六輪以上の花が咲いています。 | Hyōhon-boku de go-rokurin ijō no hana ga saite imasu. | Five or six or more flowers are open on the sample tree. |
| 平年より五日早い開花です。 | Heinen yori itsuka hayai kaika desu. | The blossoms have opened five days earlier than average. |
| 昨年より三日遅くなりました。 | Sakunen yori mikka osoku narimashita. | It's three days later than last year. |
| 満開は来週の半ばになりそうです。 | Mankai wa raishū no nakaba ni narisō desu. | Full bloom looks likely around the middle of next week. |
From bud to hazakura: the stages of the bloom
Between the first flower and the first leaves, Japanese has a word for every stage. The diagram runs left to right through a typical season. The two boxed stages, kaika and mankai, are the agency's official observations. The others are judged by eye by parks, forecasters and anyone standing under a tree.
The -bu-zaki words use bu (分), an old unit of one tenth, so gobu-zaki is literally five-tenths blooming. In Tokyo, kaika and mankai fall on average a week apart, on 24 and 31 March, and a warm spell can shorten the gap to a few days.
| Stage | Reading | What you see |
|---|---|---|
| つぼみ | tsubomi | Buds only, with pink tips showing near the end |
| 開花 | kaika | Five or six flowers open on the sample tree |
| 三分咲き | sanbu-zaki | About 30 percent open |
| 五分咲き | gobu-zaki | About half open |
| 七分咲き | shichibu-zaki | About 70 percent; already lovely for viewing |
| 満開 | mankai | About 80 percent or more open |
| 散り始め | chiri-hajime | Petals starting to fall |
| 葉桜 | hazakura | Mostly fresh green leaves, a few flowers left |
The sakura zensen: a front that moves north
Sakura zensen (桜前線), literally the cherry front line, borrows the word for a weather front. Joining places that reach kaika on the same date gives a line, and in an average year it crosses Kyushu, Shikoku and Tokyo in late March, reaches southern Tohoku around 10 April and arrives in Hokkaido from late April into May. The phrase was coined by the media in the 1960s.
The line is less tidy than the arrow suggests, and the reason is useful. Somei Yoshino needs a cold winter to wake its buds, so after mild winters southern Kyushu can bloom later than Tokyo: Kagoshima's average kaika is 26 March, two days after Tokyo's. Okinawa watches a different tree, the deep pink hikan-zakura, which opens in January, and eastern Hokkaido watches a mountain cherry. Every year differs: in 2026 Tokyo opened on 19 March, five days early. A news anchor tracks the front like this.
| Japanese | Romaji | Meaning |
|---|---|---|
| 桜前線が北上しています。 | Sakura zensen ga hokujō shite imasu. | The cherry blossom front is moving north. |
| 東北でも各地で桜が咲き始めました。 | Tōhoku de mo kakuchi de sakura ga sakihajimemashita. | Cherry trees have started blooming across Tohoku too. |
Who forecasts: observation versus prediction
Two kinds of statement are easy to confuse. An observation, kansoku (観測), reports what the sample tree has done; only the agency makes these for its official trees, and the media call the announcement kaika sengen (開花宣言), literally a blooming declaration. A forecast, yosō (予想), says what the tree will probably do.
The agency stopped forecasting after the 2009 season and left prediction to private companies. Since 2010 the forecasts you see come from firms such as the Japan Weather Association on tenki.jp, Weathernews and Weather Map. They use their own models and update them through the spring, so two sites may disagree by a day or two. A colleague organising the office viewing might say the following.
| Japanese | Romaji | Meaning |
|---|---|---|
| 開花予想によると、東京は三月二十日ごろだそうです。 | Kaika yosō ni yoru to, Tōkyō wa sangatsu hatsuka goro da sō desu. | According to the forecast, Tokyo will open around 20 March. |
| 予想が二日早まりました。 | Yosō ga futsuka hayamarimashita. | The forecast has moved two days earlier. |
| サイトによって予想が少し違いますね。 | Saito ni yotte yosō ga sukoshi chigaimasu ne. | The forecasts differ a little from site to site. |
| 開花宣言はまだですか。 | Kaika sengen wa mada desu ka. | Have they announced the opening yet? |
Beyond the basics: petals, rain and cold snaps
After mankai the vocabulary turns poetic, and it is everyday poetry that you will hear on the weather report. Hana-fubuki (花吹雪), literally a flower blizzard, is a gust that fills the air with petals. Hana-ikada (花筏), literally a flower raft, is the sheet of petals floating on a moat or river. Hanabie (花冷え) is the cold snap that often arrives during the bloom, and hana-chirashi no ame is the rain that brings the flowers down.
In spring, hana on its own usually means cherry blossom, which is why hanami is flower viewing without naming the flower. Yozakura (夜桜) is cherry blossom at night, often lit up. A weather presenter on a chilly April morning might say the following.
| Japanese | Romaji | Meaning |
|---|---|---|
| 今日は花冷えの一日になりそうです。 | Kyō wa hanabie no ichinichi ni narisō desu. | Today looks set to be chilly for blossom season. |
| 週末の雨で散ってしまいそうです。 | Shūmatsu no ame de chitte shimaisō desu. | The weekend rain looks likely to bring the blossoms down. |
| 風が吹いて、花吹雪になりました。 | Kaze ga fuite, hana-fubuki ni narimashita. | The wind blew, and the air filled with petals. |
| お堀が花筏でいっぱいです。 | Ohori ga hana-ikada de ippai desu. | The moat is covered with floating petals. |
Planning around the forecast: phrases for real conversations
The word that matters most for planning is migoro (見頃), literally the time for seeing: the days when the trees look their best, usually from shichibu-zaki to the first falling petals. In the first four lines, two colleagues choose a date for an office viewing; in the last two, a traveller asks a hotel receptionist for advice. What to say once you are sitting on a tarp with food and drinks is covered in a separate hanami guide.
| Japanese | Romaji | Meaning |
|---|---|---|
| 今、何分咲きですか。 | Ima, nanbu-zaki desu ka. | How far into bloom are they now? |
| 見頃はいつごろですか。 | Migoro wa itsu goro desu ka. | When will they be at their best? |
| 今週末が見頃だそうですよ。 | Konshūmatsu ga migoro da sō desu yo. | They say this weekend will be the best time. |
| 来週だと、もう散り始めているかもしれません。 | Raishū da to, mō chiri-hajimete iru kamo shiremasen. | By next week they might already be falling. |
| この近くで、今きれいに咲いている所はありますか。 | Kono chikaku de, ima kirei ni saite iru tokoro wa arimasu ka. | Is there anywhere near here where they're blooming nicely now? |
| 川沿いの桜がちょうど満開ですよ。 | Kawazoi no sakura ga chōdo mankai desu yo. | The cherries along the river are in full bloom right now. |
Spoken reality: how people actually talk about the bloom
In conversation, people rarely say kaika. Friends say sakura saita ne, the cherries are out, or mō saiteru?, are they out yet? Mankai is used by everyone, but the -bu-zaki words mostly live in news, park notice boards and forecasting sites; in talk people say mada tsubomi, still buds, or hanbun gurai, about half.
News language is formal and precise: kaika ga happyō saremashita, heinen yori mikka hayaku. Casual talk hedges with sorosoro, any day now, and raishū ga pīku kana, next week might be the peak. Hazakura is used by everyone, often with a sigh.
| Japanese | Romaji | Meaning |
|---|---|---|
| 桜、咲いたね。 | Sakura, saita ne. | The cherries are out. |
| もう咲いてる？ | Mō saiteru? | Are they out yet? |
| まだつぼみだったよ。 | Mada tsubomi datta yo. | They were still in bud. |
| そろそろ満開かな。 | Sorosoro mankai ka na. | I guess they'll be in full bloom soon. |
| もう葉桜だね。 | Mō hazakura da ne. | It's all leaves already. |
Common mistakes when reading sakura news
Going on the day of kaika. The word sounds as if the season has arrived, but it means five or six flowers on one tree, and the trees around you will be mostly buds. Aim for a few days before mankai to a few days after.
Treating the forecast as an official timetable. Forecasts come from private companies and move with the weather. Check again in the week before your trip, and keep yosō, forecast, separate from kansoku, observed.
Assuming the south always blooms first. Because Somei Yoshino needs winter cold, Tokyo often beats Kagoshima. Compare the heinen dates for the cities on your route instead of guessing from the map.
Reading mankai as 100 percent. Mankai starts at about 80 percent, so a tree can be officially in full bloom with some buds still closed. That is often the best moment: the tree is full and nothing has fallen yet.
Thinking hazakura is a kind of cherry. It is a stage: the same tree a week or two after mankai. Yaezakura, double-flowered cherries, bloom later than Somei Yoshino, so a park of hazakura may still have late flowers nearby.