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 16 rainy, 9 partly cloudy, 5 cloudy, and 1 sunny day in July. The rains are usually heavy. July as well as March, April, May, and June is considered the most uncomfortable time to visit Invercargill.