The air temperature between the clouds and the ground must be at or below 32 F. [0 C], the freezing point of water, for snowflakes to form.
(The air temperature between the clouds and the ground; must be; at or below 32 F. [0 C], the freezing point of water) (snowflakes; to form; )
The air temperature between the clouds and the ground snowflakes
must be to form
at or below 32 F. [0 C], the freezing point of water