It is the right time of year (at least in Colorado) to talk about the trinity of winter deities – Valind, Inora, and Himile. These gods are much more important than their tiny cults would suggest.
Valind is the Winter King. He is a dangerous and powerful god who brings the winter storms, snow, and ice across Genertela. In the Lesser Darkness he ruled much of the world, and his glacier – a vast accumulation of ice and snow – displayed his might. Each winter, he advances from his glacier stronghold and tries to conquer Genertela. He is initially aided and later opposed by his storm god kinsfolk, but he always is eventually forced back so that spring can occur.
In recent decades, the Lunars send an annual group of heroquesters to fight him on the glacier and force him back, as the ancient hero Kallikos did before Time. This has weakened his advances into Peloria, and shortened winter. But Valind himself remains powerful and has built up resentment against Peloria like a river against a dam. Now if the Lunar heroquesters ever fail, winter will return with a terrible vengeance.
Inora is the goddess of the snows, particularly the mountain snows that remain year round. In some lands she is viewed as an enemy; in others she is the primary source of water and fertility. She is the half-sister of Orlanth and an ally of Valind.
Himile is the god of cold itself, a dark and hungry god, even more terrible at night than day. He is perhaps the most dangerous of the three gods of winter, but the least obvious.
Xentha is ambivalent about winter, as she is the goddess of both the freezing nights when Himile is present, and the warm nights of Nochet.
Among humans these deities are usually either propitiated OR called upon against enemies. They are not particularly socially useful gods. But being able to call down snow in a battle can be really darned useful!