January in Oskarshamn is the snowiest, the cloudiest, and the coldest month of the year. In January, the weather in Oskarshamn is typically freezing. Average daily high temperature in January is about zero. On average, Oskarshamn has 17 cloudy, 6 rainy, 6 snowy, and 2 sunny days in January. The rains are usually light. January as well as February, November, and December is considered the most uncomfortable time to visit Oskarshamn.