Planning for the weather is an important factor for making your trip to Shenzhen a success, especially when you're splurging. The hottest months are usually August and July, with an average temperature of 29°C, while the coldest months are January and December, with an average of 18°C. The rainiest months in Shenzhen are August, June, May and July, with each month seeing an average of 294 mm of rainfall.