When shoveling it, brushing it off, whisking it aside or cursing its very presence, it’s easy to forsake the beauty of snow. But catch one on your mitten and you’ll see a sparkly little wonder that, together with its brethren, looks like a field of diamonds on a cold sunny day.
Yet the question remains: Is it true that no two snowflakes are alike?
The search for an answer starts with a microscopic piece of dust or some other particle that can collect moisture from clouds. As the moisture freezes into ice crystals, they adhere together to form a snowflake.
The amount of moisture in the air and the temperature determine the size and shape of each flake—the warmer the air, the bigger the crystal and the more complex its shape. Deep freeze temperatures form elongated crystals that ping windows and hurt when they hit your face. Temps that hover just below zero degrees form snowflakes reminiscent of those that kindergarteners cut out from paper. The really fancy, detailed snowflakes—those that are easy to examine—are formed at temps around 20˚F.
Through the years, meteorologists described dozens of different shapes of snow crystals and, by 1951, the International Commission on Snow and Ice presented snowflake classification guidelines. It was determined that there are seven kinds of snow crystals segregated by the temperature in which they form and the look of them once they’ve fallen to earth. The former has the biggest impact on snowflake shape—why this happens “is something of a scientific puzzle,” said author Ken Libbrecht in Ken Libbrecht’s Guide to Snowflakes.
As for the “no two alike” theory, it’s difficult to say. If you could somehow see every snowflake that falls during a given winter, you might find some that appear alike. Mathematics very much comes into play. The chances of two snowflakes being alike are astronomical.
When faced with moving all those snow crystals, it’s easy to see them as one. Shoveling is better when the ground temperature is super cold since it results in the fluffy, can’t-make-snowballs stuff. A temp more than 15˚F makes for great snowballs, excellent snowmen and stickier (if not dissimilar) snowflakes.