The weather is a favourite topic of conversation in Japan. This is unsurprising given the complexity of the climate in a country spanning 20 degrees of latitude.
From the harsh winters and mild summers of Hokkaido to the sub-tropical Okinawan climate there is a great variety in Japanese weather. Even in the same city both extremes of weather can be experienced in a year - Sapporo in Hokkaido can experience temperatures of minus 10 in the winter but heat waves of 30 degrees in the summer are not a rare occurrence.
On the mainland, summer temperatures are generally between 20 and 30 degree centigrade. In the early part of summer (mid-June to mid-July) there is a rainy season lasting a few weeks, this is however broken up by days of fine weather. Rains come again in late summer thanks to typhoons, although these usually blow over in a day.
- See more at: http://www.insidejapantours.com/travel-tips/#sthash.IH8Y55o1.dpuf