Is the rain in Shanghai acidic or alkaline?

Weak acidity. The rain in Shanghai is weakly acidic. Nitrogen dioxide in the air reacts with water to produce carbonic acid, which is a weak acid, so rain is a weak acid. When the ph value is about 5.6, it belongs to acid rain when the ph value is less than 5.0. Rain is a solar term reflecting precipitation phenomenon and a reflection of ancient farming culture on festivals. As the saying goes, "Spring rain is as expensive as oil", and suitable precipitation is very important for the growth of crops.