Sendai has a moderate and humid subtropical climate. Temperatures are reasonable throughout the year, though the dry winters can bite a little. Still, it does have distinctive seasons. Six weeks of June and July are the city’s wettest. Spring and autumn are the prettiest times of the year, and there’s no way to differentiate them for sheer value. The peak season to visit for families is spring (especially hanami time in April); for couples it is autumn. There’s no real off season. The temperature breakdowns of the seasons are as follows:
Spring: March – May: Starting out chilly with daily averages of 4.5 degrees Celsius, the days warm up to highs of 20 degrees Celsius in May, though the nights remain cool even then at 11 degrees Celsius.
Summer: June – August: Night temperatures remain pleasant, with the mercury at 21degrees Celsius even in the hottest month, August, which has day highs of 28 degrees Celsius. June and July days, though rainy, don’t feel so bad thanks to cold winds from the north.
Autumn: September – November: September weather mirrors July, with daily averages of 20 degrees Celsius. October is the most pleasant month of this season, before the mercury falls sharply in November, when the nights are around 5 degrees Celsius.
Winter: December – February: Temperatures don’t fluctuate much through winter, though December is noticeable warmer at 4.3 degrees Celsius. Night temperatures hover below zero in January and February, rising to 5 degrees Celsius in the daytime.