Winter sea-ice extent of Davis Strait which is strong information for July rainfall of North China is negatively correlated with July rainfall of North China.

• 冬季戴维斯海峡海冰面积与华北7月降水在年际变化尺度上有明显的反相关关系。 冬季戴维斯海峡的海冰面积增多(少)，同年华北7月降水偏少(多)。