卷积云（Cc），拉丁文学名Cirrocumulus。似鳞片或球状细小云块组成的云层或云片，多成群、成行出现，排列规则。色白无暗影，有柔丝般光泽。卷积云只有一类云状。

• 天空中辐射状的卷积云。

• 由许多小云聚集而成的片状卷积云，照片上方则是两朵破碎积云。

Cirrocumulus is one of the three main genus-types of high-altitude tropospheric clouds, the other two being cirrus and cirrostratus. They usually occur at an altitude of 5 kilometres (16,000 ft) to 12 kilometres (39,000 ft). Like lower altitude cumuliform and stratocumuliform clouds, cirrocumulus signifies convection. Unlike other high cirrus and cirrostratus, cirrocumulus includes a small amount of liquid water droplets, although these are in a supercooled state. Ice crystals are the predominant component, and typically, the ice crystals cause the supercooled water drops in the cloud to rapidly freeze, transforming the cirrocumulus into cirrostratus. This process can also produce precipitation in the form of a virga consisting of ice or snow. Thus cirrocumulus clouds are usually short-lived. They usually only form as part of a short-lived transitionary phase within an area of cirrus clouds and can also form briefly as a result of the breaking up of part of a cumulonimbus anvil.