You'll likely spend much of your trip indoors, 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 25°C, while the coldest months are January and February, with an average of 7°C. The rainiest months in Yachiyo are October, September, June and July, with each month seeing an average of 183 mm of rainfall.