Oxygen atoms about 100 to 150 miles above us glow a deep red, and this is the rarest color seen. Nitrogen molecules glow pink at that height and in the blue-violet range at lower altitudes. Magnetic field lines and the energy output of the solar windstream create the many shapes, which include arcs, bands, rays, pillars, draperies, and coronas. Aurora may be seen as soon as the first stars appear and until the last star disappears. They have been witnessed from sunset to dawn and every minute in between.
Displays occur more often in the polar regions.
The farther north towards the earth's magnetic poles, the more frequent the Aurora sightings. Depending on your latitude, Aurora may be seen from a very large geographic area. Over 200 nights in Fairbanks, over 100 nights in Anchorage, less than 100 nights in southern Canada, and less than 50 nights a year in the northern tier states. In the deep South the Aurora may be seen once every 10 - 30 years. The temperature on earth has absolutely nothing to do with the Aurora.