The question of which month constitutes the start of winter in the USA is a bit more complex than it seems. While many people assume that winter begins on December 21 or 22, the exact date can vary slightly from year to year. Moreover, the United States spans a large geographical area, encompassing a wide range of climates and regions, each with its own distinct seasonal patterns.
The United States is massive, so "winter" looks very different depending on where you are.