Since we are part of the country setting record lows in January 2014, we decided to take a break from our balloon podcasts to try a classic cold weather demonstration – making snow.
As if we didn’t have enough of it already. I know.
The short answer as to why hot water turns into snow but cold water doesn’t is that hot water is closer in state to steam than the cold water is. That in turn means that the water breaks up into smaller droplets more easily, and can freeze more easily (smaller droplets freeze more quickly than larger ones). The cold water holds onto itself longer, so it doesn’t freeze as quickly.
A more detailed explanation can be found at HowStuffWorks.com.