Sendai, the largest city of the Tohoku region, sits on the Pacific coast of northeastern Honshu, on a plain between the Ou mountains and the sea at approximately 38.27°N, 140.87°E. It has a humid subtropical climate (Köppen Cfa) at its northern limit — with mild, humid summers and cold winters — moderated by the Pacific and sheltered from the heavy snow that buries the Sea of Japan coast.

Summer, from June to August, is warm and humid rather than sweltering, with August the warmest month — average highs around 27–28°C — noticeably cooler than Tokyo thanks to the yamase, a cold, damp easterly wind off the Pacific that can bring fog and overcast skies. The baiu plum rains fall in June and July, and late summer brings the risk of typhoons.

Winter, from December to February, is cold but comparatively dry and sunny, with January the coolest month — average highs around 5–6°C and lows near -2°C. The Ou mountains to the west strip the moisture from the cold Siberian winds, so Sendai sees far less snow than the Sea of Japan side of Tohoku, and clear, crisp winter days are common.

Sendai receives around 1,200–1,300 mm of precipitation a year, concentrated in the baiu rains of June and July and again in the autumn typhoon season, while winter is drier and much less snowy than the western side of Tohoku. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

Sendai's summers are cooled by the yamase, a cold, moist easterly wind off the chilly Oyashio current that can shroud the Tohoku coast in fog and, in bad years, damage the rice harvest by suppressing summer warmth. Its coastal plain, devastated by the tsunami of March 2011, also faces the Pacific's typhoons in late summer.

To follow any single measurement in Sendai more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.