In May, the weather in Tomakomai is typically warm. Average daily high temperature in May is about 13 degrees above zero. On average, Tomakomai has 12 rainy, 7 partly cloudy, 6 sunny, and 6 cloudy days in May. The rains are usually moderate. May as well as March, April, July, and November is considered the most uncomfortable time to visit Tomakomai.