Weather forecast in Zhongshan, Guangzhou

A, the clouds are thin on sunny days, and the weakening effect of the atmosphere on solar radiation is weak, which does not meet the meaning of the question;

B, the clouds are thin on sunny days, and the atmospheric inverse radiation is weak at night, which is correct;

C, in sunny days, the weakening effect of cloud thickness is weak, so the ground radiation is strong, but because of the thin clouds, the ability of the atmosphere to absorb ground radiation is weak, so it does not meet the question;

D, the temperature is high in sunny days and low at night, so the daily temperature difference is large, which does not meet the question.

Therefore, choose: B.