This is the season of Aurora Borelis (Northern Lights). The image above was taken on March 11, 2012.
As you may suspect, the best place to see the Aurora Borealis is from high latitudes up north. More specifically, anywhere you can get to that's within 2500km from the North Pole. That includes a number of countries, like Finland, Norway, Sweden, Russia, Canada, Greenland and USA (only Alaska). All these countries have regions that fall into this region. The northern areas of all these countries is where you'll want to be.
The phenomena called aurora is a natural light display in the sky particularly in the high latitude (Arctic and Antarctic) regions, caused by the collision of energetic charged particles with atoms in the high altitude atmosphere (thermosphere). The charged particles originate in the magnetosphere and solar wind and, on Earth, are directed by the Earth's magnetic field into the poles atmosphere.
Since the charged particles are directed by Earth's magnetic field lines you can actually see the Northern Lights from the South Pole. So, why don't they call it the Southern Lights?