You might spend a lot of your holiday inside, but if you're planning to venture beyond the casino, taking a look at local weather data can help you. The hottest months are usually August and July, with an average temperature of 23°C, while the coldest months are January and February, with an average of 5°C. The rainiest months in Eiheiji are July, December, September and January, with each month seeing an average of 294 mm of rainfall.