There are two North Poles. The one most people think of is the geographic North Pole, which is located approximately 450 miles (724 kilometers) north of Greenland, at 90 degrees north latitude.
Because all lines of longitude converge at the North Pole, it's not technically in any time zone (or, it's in every time zone, depending on your perspective). As a result, we generally use Coordinated Universal Time (UTC) at the North Pole. Coordinated Universal Time is used mostly in astronomy and navigation: It's similar to Greenwich Mean Time (the time kept on the Greenwich meridian, longitude zero) but scientifically more precise.
The sun sets at the North Pole in early October. The next sunrise is in early March. In between, there's a continuous twilight as the Earth moves on its axis. See What causes the seasons? for more on why the North Pole has continuous sunlight during the Northern Hemisphere's summer and continuous darkness during the winter.
As a result of all this, the North Pole is obviously cold. In the winter, when the North Pole is farthest from the sun on the Earth's axis, the average temperature is -40 degrees Fahrenheit (-40 Celsius) during December and January, but can dip into the negative 50s [sources: Smith, Goddard Space Flight Center]. The seawater beneath the ice of the North Pole is a relatively mild -28 degrees F (-33 C). In the summer, the Pole averages 32 F (0 C). But the North Pole isn't as cold as it used to be. To learn more about the melting ice, read Why is Arctic ice melting 50 years too fast?
What kind of wildlife can survive at such temperatures? Read on to find out.