Refer to figures.
Among the meteorological factors determining the rate of icing accretion are the amount of liquid water present and the size of the droplets. These characteristics are not the same throughout a particular cloud, even at one level:

A cloud containing both liquid water and ice crystals may have large patches where one or the other predominate and icing will tend to be severe when the temperature is not far below 0°C. An analysis of reports on ice accretion shows a preponderance of occasions at temperatures above about - 10°C and indicates that the frequency diminishes rapidly when the temperature falls below - 20°C, although occasional icing has been reported at temperatures below - 40°C.

• RIME ICE: Normally encountered in stratiform clouds. In these clouds, continuous icing can be expected in the temperature range from 0°C to -30°C, and results from instantaneous freezing of small supercooled water droplets striking the aircraft’s surface.
• CLEAR ICE: Most heavily concentrated in cumuliform clouds (dense clouds) in the range of temperature from 0°C to -15°C.