what makes it rain? rain fallas from clouds for the same reason reason anything falls to earth. the earth's gravity pulls it but every cloud is made of water droplets or ice crystals. why doesn't rain or snow fall constantly from all clouds? the droplets or ice crystals in clouds are exceedingly small. the effect of gravity on them is minute. Air currents move and lift droplets so that the net downward displacement is zero, even though the droplets are in constant motion.