July in Invercargill is the coldest month of the year. In July, the weather in Invercargill is typically cold. Average daily high temperature in July is about 9 degrees above zero. On average, Invercargill has 23 rainy, 4 sunny, 3 cloudy, and 1 partly cloudy day in July. The rains are usually moderate. July as well as January, March, April, and May is considered the most uncomfortable time to visit Invercargill.