according to the query of Baidu Chinese website, it is a common saying in Tomb-Sweeping Day that it is sunny and cloudy in spring, and it is sunny and rainy until Qingming, which means that most days are cloudy due to the weather and thunderstorm in the vernal equinox, so it is half sunny and half rainy until Qingming. Described the weather conditions in Tomb-Sweeping Day in spring.
Tomb-Sweeping Day originally meant Tomb-Sweeping Day, 15 days after the vernal equinox. In 1935, the government of the Republic of China designated April 5 as a national holiday, also known as the national grave-sweeping festival.