What aerosols, solid or liquid, do clouds in the Earth’s atmosphere consist of?

In summer, low clouds are, of course, water droplets suspended in the air. However, at high altitudes, clouds even in summer can consist of ice crystals, as evidenced by the cases of hail and the existence of noctilucent clouds. In winter, clouds are also predominantly water droplets. The crystallization of water droplets depends on the presence of crystallization centers in them (dust particles, etc.). The smaller the drop, the greater the likelihood of the absence of irregularities in it. Therefore, small droplets may not freeze even at very low temperatures. Droplet hypothermia is possible even down to -40 ° C.