Mostly literary; you'll meet 霄 inside compounds rather than alone — 云霄 (yúnxiāo, the high heavens), 九霄 (jiǔxiāo, the highest heavens), 霄汉 (xiāohàn, the sky and the Milky Way), 霄壤之别 (xiāorǎngzhībié, a difference like that between sky and earth).
memory
Top radical 雨 (rain) signals weather/sky; 肖 below gives the sound. Original meaning was 'sleet,' which broadened to 'sky / high clouds.'
