Winter is synonymous with cold temperatures, frost, ice, frigid winds, and snow. Around the globe, snowfalls accumulate during the winter months. Estimates put the number of snowflakes that fall from the sky each winter at one septillion. That's a trillion trillion, or a one with 24 zeroes behind it. Considering the amount of individual snowflakes it takes to make up that number, it makes sense that some patterns in the flake structure would repeat. But scientists who study snowflakes attest to the unique pattern of each individual snowflake. Some may appear similar but upon closer inspection, differences become apparent in all cases. Source: Blogs.LOC.gov
Interesting fact:
This is the amount of snowflake crystals that fall across the globe each year.