Sapporo (Hokkaido) — sää kuukausittain

April here runs weeks behind mainland Japan and the board says so twice over. The blossom peaks around the end of the month rather than the start, so a trip timed to Honshu's cherry season arrives here far too early. And winter has not finished: regulars report fresh snow falling in late April, twenty centimetres at a stroke, which our column backs at 22.9cm across the month. The row reads 12.8C by day but only 10C to stand in, over 4C nights that feel like 1C in a 16.2 kph wind, with 81.3mm of precipitation across 12.1 days. A coat, and gloves in the evening if you feel the cold. The record: humidity 76 percent, 9.7 hours of sun and AQI 53.

May is when Hokkaido finally turns: the snow has gone from the towns, the weather is getting drier and sunnier, and the cherry blossom reaches Sapporo about a week after Hakodate, over Golden Week, with Maruyama Park the busy spot. Late May is the part regulars describe as lovely, with spring flowers everywhere. What they warn about is the temperature, which is still well below the rest of Japan - around 10C on their reckoning, and below that at night - against our row's 18.8C days and 9.5C nights, with 0.8cm of snow still inside the monthly normal. Eastern Hokkaido is cooler again. The record: 12 precipitation days carrying 87.9mm, 10.2 hours of sun and an 11.4C sea.

Hokkaido's forum calls June the pick of the year for anyone wanting reliably sunny weather in Japan — the island sits outside the country's rainy season entirely. Regulars put late-June days in the low-to-mid 20s°C with nights in the mid-teens, and flag mid-June as when Sapporo's parks come into peak bloom.

Hokkaido is where people go to escape the Japanese summer and regulars are honest about how much escaping it does: less hot and less muggy than Tokyo or Kyoto, but 20 to 30C with real humidity, and days above 30C do happen this far north. Our row agrees - 26.4C reading as 30C at 86 percent. What July adds is a calendar. The Sapporo Summer Festival runs from the middle of the month to the middle of August, fireworks fall on set July dates, the lavender is out until late July and the sunflowers start as it ends, so a late-July visit catches both. Rain is real at 129.7mm across 12.7 days. The record: 18.8C nights, 9.9 hours of sun inside 15 of daylight.

September splits in two on the Sapporo and Hokkaido forums: early September can be wet, and the advice is to aim from the third week onward. Typhoons come up constantly and the regulars' answer is reassuring - Hokkaido is rarely hit at any time of year, because systems have usually petered out by the time they get this far north, though passing fronts and typhoon remnants still put rain on the calendar. Temperatures around 20C are the expectation, with days warm enough to walk in and evenings that want a jacket. Late September is also the start of the leaves, and posters note colour depends on elevation - if the city has none yet, go up. The record: 23.3C days, 14.9C nights, 12.7 precipitation days carrying 131.1mm, 8.6 hours of sun, AQI 36.

Regulars are specific that late in this month sits in a genuine lull - autumn colors from early-to-mid October already fading, while the city's famous snow hasn't yet arrived, making late October a quieter, less dramatic stretch for anyone timing a visit around either spectacle. Our row backs that cool, genuinely wet read, 16.2C over 7.7C nights feeling 5C, with 109mm of rain across 14.4 days and a first trace of early snow, 5.2cm. Regulars are consistent early-to-mid October remains the better window specifically for fall foliage, with temperatures then still comfortable in the 10-15C range for walking. A warm layer over a waterproof shell covers most of what the month can bring regardless of which week is chosen. The sea sits at 18.5C. The record: humidity 78 percent, 7.9 hours of sun, a 15.2 kph wind and AQI 37.

Forum posters describe snow cover building steadily through December: it starts sticking around the city from mid-November, so by early December it's typically covering most outdoor surfaces, and by late December it's packed onto roads and sidewalks citywide. Early December itself is the least reliable stretch - some years see more rain than snow right at the start of the month, with accumulation not fully guaranteed until later in December. Visitors chasing guaranteed snow early in the month are steered toward Niseko and other mountain resort areas further north, which reliably have accumulation before the city does. Icy, packed-snow sidewalks in parts of the city are a real practical consideration by this point in the season.