Articuno is traditionally portrayed as a vengeful god of winter, and this is reflected in most of the legends about them. There is the one where, if one is to make eye contact with it or challenge it to a battle, it will gaze into their soul, and if they fail to slay it instantly, it shall judge them (or "you", for the story is often told as a warning) and turn every cell of their body to ice.
There is the one about weather, for Articuno have always been blamed even for mild flurries. Snow comes from the sky and often with wind, so the prophets of old need not have pointed to them for them to inevitably be associated with blizzards. For instance, there is a story of an Articuno that roosts on a large blue hill east-northeast of Unova and soars around the land every winter, creating blizzards with each flap of its wings. Similar tales exist in Sinnoh of one on Mount Coronet, and perhaps all around the world where snowstorms and Articuno alike are known.
And then there is the one of it appearing to lost travelers and guiding them to their doom, a well-known tale whose standard form needs no elaboration. Curiously, a variant of the myth shows a softer side, where Articuno attempt to lead them to safety. The travelers in this version of the story have heard that Articuno bring doom, run the other way, and freeze to death on a mountainside. Perhaps this shows that Articuno have a friendly side, and the people who tell this tale have been aided by them in ages past, but perhaps it is merely a satire reflecting on the dangers of getting lost in icy mountains or taking myths at face value.