October in Sydney is the rainiest month of the year. In October, the weather in Sydney is typically warm. Average daily high temperature in October is about 12 degrees above zero. On average, Sydney has 13 rainy, 8 partly cloudy, 6 sunny, and 4 cloudy days in October. The rains are usually heavy. October as well as April, May, November, and December is considered the most uncomfortable time to visit Sydney.