On average across the year, no, Estonia is not hotter than Japan . Estonia has an average temperature of 7°C/45°F and Japan has an average temperature of 15°C/59°F.
Estonia's hottest month is July, with an average maximum temperature of 23°C/73°F, which is not hotter than Japan's hottest month (August, with an average maximum temperature of 32°C/90°F).
On average across the year, yes, Estonia is colder than Japan . Estonia has an average minimum temperature of 3°C/37°F and Japan has an average minimum temperature of 11°C/52°F.
Estonia's coldest month is January, with an average minimum temperature of -6°C/21°F, which is colder than Japan's coldest month (also January, with an average minimum temperature of 0°C/32°F).
On average across the year, no, Estonia has less rain than Japan. Estonia has an average annual rainfall of 426mm and Japan has an average annual rainfall of 1632mm.
Estonia's wettest month is January, with an average monthly rainfall of 49mm, which is drier than Japan's wettest month (July, with an average monthly rainfall of 218mm).