How long has it rained since beginning of spring?

About 15 days. According to the query of China Meteorological Network, the solar term in beginning of spring is generally around February 4th, and the solar term in rain is generally around February 19, so the solar term in beginning of spring will be around 15. Beginning of spring is the first of the 24 solar terms. Standing means "start"; Spring represents warmth and growth. Twenty-four solar terms were originally formulated on the basis of "variable stars". When the bucket handle of the Big Dipper points to the shade, it is beginning of spring. At present, solar terms are determined according to the longitude of the sun. When the sun reaches longitude 3 15, it will be the beginning of spring, and the festival will be held from February 3 to 5 of the Gregorian calendar every year.