The Largest Snowflake Ever Observed

The largest snowflake ever observed supposedly appeared on 28 January, 125 years ago, in Fort Keogh, Montana. It was reportedly 15 inches wide and 8 inches thick. However, this record seems to be based on the word of a ranch owner named Matt Coleman, who described the snowflake as “larger than milk pans” to the Monthly Weather Review journal.

This record seems a bit dubious, however, as the National Snow & Ice Data Center notes in its FAQ section regarding how big snowflakes can get:

“Snowflakes are agglomerates of many snow crystals. Most snowflakes are less than one-half inch across. Under certain conditions, usually requiring near-freezing temperatures, light winds, and unstable, convective atmospheric conditions, much larger and irregular flakes close to two inches across in the longest dimension can form. No routine measure of snowflake dimensions are taken, so the exact answer is not known.”