When winter weather gets unusually cold, people sometimes say that the weather is Arctic. Sometimes that is true, because Arctic air often spreads southward in winter to regions well outside the Arctic Circle. Weather and climate in the far north are very different than weather and climate in the middle and lower latitudes, where most people live, but it is not always bitterly cold. Summer days can be surprisingly warm, even in tundra regions, and summer thunderstorms in the Arctic are common, sometimes setting forest fires.

Arctic tundra in the winter. Lake Myvatn, Iceland.
—Credit: Flickr/Lukás Hejtman.

Arctic tundra in the summer. Kola Pennisula, Russia.
—Credit: Flickr/A. Maksimov.