Planning for the weather is a good way to make your trip to Hwaseong relaxing and enjoyable, especially when you're splurging. The hottest months are usually August and July, with an average temperature of 24°C, while the coldest months are January and December, with an average of 1°C. The rainiest months in Hwaseong are July, August, September and June, with each month seeing an average of 224 mm of rainfall.