Clouds are a lot cooler than you might think. In fact, scientists might say they're super cool because they're made up of millions of supercooled water droplets, droplets that have been cooled below the freezing point but haven't yet turned into ice. When these droplets freeze, they can accelerate freezing of the whole cloud through a process called secondary ice production. This is a rapid, complex process that happens across different time and length scales.
