If you're looking for summer vibes, the best time to travel to Sendai is in July, August and September, when the average temperature reaches 23.03 °C, while May, April and March are the 3 sunniest months of the year, with an average of 20.6 hours.
If you prefer colder temperatures, however, make sure you visit Sendai during the months of January, February and December to experience an average of 2.04 °C.
For those who don't care too much about temperatures, but want to avoid getting wet in the rain, it's important to avoid travelling during January, February and April, when the average precipitation in Sendai is 5.25 mm, while the months of January, February and March are drier, with an average of 0 mm.