Hokkaido is the only part of Japan without a rainy season.

Hokkaido month by month, at a glance

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Jan

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Jun

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Dec

Between early June and mid-July, almost all of Japan is under the tsuyu, the rainy season that arrives from the south and leaves weeks of closed sky and high humidity. Hokkaido is not. It is the only region of the country without one, and that fact alone organises the island's calendar: while the rest of the archipelago is in its worst month, June here gives 60.4 millimetres of rain, 180 hours of sunshine and a mean daily maximum of 21.8 degrees.

A panorama of a sloping field entirely covered in red, pink and white poppies, a band of green grass behind, a mown hill beyond and a line of conifers closing the horizon. — July on the hills of Biei. It is the month when Hokkaido has heat, light and bloom at once.雷太 / CC BY 2.0·CC BY 2.0

01 June: sixty millimetres

The figures are for Sapporo, the 1991-2020 series. June brings 60.4 millimetres over 9.3 rain days, with maxima of 21.8 degrees and minima of 13.4. Only April and May are drier, and neither has that temperature.

The practical consequence is that June in Hokkaido is one of the best dates in all of Japan, and the least contested: anyone travelling in the country during those weeks is usually looking for a way out of the south. The island is that way out, and it costs less than in high summer.

02 Summer gets wet at the end, not the start

Here is the nuance usually missed. No tsuyu does not mean the whole summer is dry: it means the water arrives later. July brings 90.7 millimetres; August 126.8; and September 142.2, the year's maximum. The tail of the typhoon season reaches this far north weakened but it reaches it, and September is its month.

So the summer window is not “June to September” but “June and July”. In August the island is still far more bearable than Tokyo — 26.4 degrees against the mid-thirties in the south — but it is already raining, and in September it rains properly.

Key moments at a glance

JunNo rainy season

60.4 mm and 180 hours of sunshine while the rest of Japan is in the tsuyu.

JulThe lavender

25.4 °C and peak bloom at Furano in the middle of the month.

FebDrift ice

The second half is the best time of year to see it, with 116 cm of snow.

SepThe wet month

142.2 mm, the year's maximum, with the tail of the typhoon season.

03 Four metres eighty of snow

The other end of the year is just as emphatic. Sapporo receives an average of 479 centimetres of snow a year, which makes it one of very few large cities in the world with figures like that. It arrives like this: 137 centimetres in January, 116 in February, 113 in December and 74 in March.

January temperatures are −0.4 maximum and −6.4 minimum, which for a city of nearly two million is a notable anomaly. It is not an extreme winter in absolute terms: it is a very long one with an amount of solid precipitation that few inhabited places match.

A stand of leafless deciduous trees with snow loaded on their branches, over completely white, smooth ground crossed by cleared paths, under a deep clear blue sky. — January in Sapporo: 137 centimetres of snow fallen in a single month, and clear days between snowfalls.ノボホショコロトソ / CC BY 4.0·CC BY 4.0

For a traveller that carries one concrete advantage: snow is guaranteed from December to March, no gambling required. And one equally concrete disadvantage: the day is short and the secondary roads demand a different way of driving.

04 The drift ice has dates

The strangest thing that happens in Hokkaido happens in a narrow window. The sea ice coming down from the Sea of Okhotsk reaches the coast around Abashiri between the middle and the end of January, and disappears between late March and mid-April. The best time to see it is the second half of February.

The tourist icebreakers run roughly from 20 January to 31 March, on crossings of about an hour. Outside that window the same coast is simply a grey coast: nothing to see and nothing to book. It is the clearest case on the island of the date overriding every other consideration.

A sea covered in white ice floes drifting on grey water, with a broad snow-covered mountain dominating the background through a bluish haze. — The ice reaches the Okhotsk coast in late January and is gone by late March. Outside that window there is nothing to see.pakku / CC BY 3.0·CC BY 3.0

05 The lavender has dates too

At Furano the lavender starts flowering in late June, peaks between mid-July and early August, and is usually best in mid-July, when the early and late varieties overlap. Outside that, the fields are green fields.

This is worth saying plainly because the mistake is expensive: plenty of people build a Hokkaido trip around a photograph of lavender and arrive in late August, when it has already been cut. The bloom lasts about three useful weeks, not a summer.

06 The honest summary

June if what you want is the best combination of sunshine, temperature and price, and above all if the trip also takes in parts of Japan that are unusable in June. Mid-July if the aim is the lavender. The second half of February if the aim is the ice. And May as the quiet option: 55.5 millimetres, 17.9 degrees and 200.4 hours of sunshine, the sunniest month of the year.

The months to avoid are September, as the wettest, and November, which gathers the worst of both seasons: 113.8 millimetres of water, 30 centimetres of snow still insufficient for anything, and days already short.