July in Tomakomai is the rainiest month of the year. In July, the weather in Tomakomai is typically warm. Average daily high temperature in July is about 21 degrees above zero. On average, Tomakomai has 18 rainy, 9 cloudy, and 4 sunny days in July. The rains are usually heavy. July as well as March, April, May, and November is considered the most uncomfortable time to visit Tomakomai.