July in Slovenj Gradec is the warmest month of the year. In July, the weather in Slovenj Gradec is typically warm. Average daily high temperature in July is about 23 degrees above zero. On average, Slovenj Gradec has 18 rainy, 8 sunny, and 5 partly cloudy days in July. The rains are usually heavy. July as well as January, February, March, and April is considered the most uncomfortable time to visit Slovenj Gradec.