https://pubmed.ncbi.nlm.nih.gov/3057320/

I get to go old school with this reference. Basically male and female circulation systems act differently in cold weather. Men tend to keep blood flowing to all their extremities in cold weather, women tend to keep your core temperature consistent and reduce the flow of blood to extremities.

So men don’t feel as cold, but they’re burning more energy, and their core temperature can dip more. Women feel colder, but they’re core temperature is more stable, and doesn’t dip as much.

In real life we experienced this as women are often colder in the same environment men are comfortable in. Because of physiological differences in blood flow during cold weather events.

So legs stockings are both an effort to keep the body warmer, be fashionable, and maybe do some body shaping. But you’re more likely to see them in the winter, in colder climates.

Anecdotal data: in Southeast Asia I never see leggings, even in " winter ". In Japan I see leggings all the time.