April in Lanzhou is the windiest month of the year. In April, the weather in Lanzhou is typically warm. Average daily high temperature in April is about 18 degrees above zero. On average, Lanzhou has 11 partly cloudy, 9 sunny, 5 rainy, and 5 cloudy days in April. The rains are usually light. April as well as May and June is considered the most comfortable time to visit Lanzhou.