If you’re looking forward to lots of outings with your partner, take a look at these details about year-round temperatures in Ruisui: The hottest months are usually July and August, with an average temperature of 25°C, while the coldest months are January and February, with an average of 17°C. The rainiest months in Ruisui are May, August, June and September, with each month seeing an average of 458 mm of rainfall.