In April, the weather in Kalgoorlie-Boulder is typically warm. Average daily high temperature in April is about 25 degrees above zero. On average, Kalgoorlie-Boulder has 17 sunny, 8 partly cloudy, 3 rainy, and 2 cloudy days in April. The rains are usually light. April as well as May, September, and October is considered the most comfortable time to visit Kalgoorlie-Boulder.