Blackrock before, it wasn't always blizzarding every other day, not cold all year round. It was beautiful, green and blooming in spring. Warm and shining in summer.

It changed, the reason as to why...

A long time ago, the first zombie breakthough happened, its still a mystery what could cause the deity Venomshank to do so. But since then, he was not well liked in Blackrock, even forbidden to worship. The destruction his zombies caused, the lives they took... Blackrock was on the brink of becoming history.

Until Icedagger stepped up, he showered the fields and forests with ice and snow. Trapping the zombies in ice, saving Blackrock, but dooming it to eternal winter.

This also ties to Icedagger ?being mostly absent? (Maybe it was retconned now) as all of his power goes into keeping Blackrock's ice strong enough to contain the plague.