The sun has a heartbeat. Every 10 or 12 years it beats, and it beats hard. This is known as the solar cycle and is measured by the number of sunspots visible on the sun. The more sunspots, the more solar flare energy is being released into space which means more aurora activity!
Q: Where are we now on the solar cycle?
A: We are in the peak phase! Since solar minimum in 2008, sunspot activity has been on the rise and "Solar Max" is predicted for the year 2013.
Q: When is the best time to see the northern lights?
A: Between 11 pm and 2 am but they can show up anytime from dusk until dawn. Statistically, the equinox months of September and March are the best for aurora activity but the winter months of October-thru-February are also good. In northern latitudes like Alaska the summer months of May, June & July are too bright to see the aurora. Mythbuster: Contrary to popular belief, it does not have to be cold to see the aurora, just dark and clear.
Q: When should I plan my aurora hunt?
A: 2012-thru-2014 are peak years but it's challenging to pinpoint the exact timing of a big display. The best advice I can give is to be patient, diligent and pay close attention to the websites that monitor space weather, then go for it when the timing seems right. Luck favors the prepared.
Historical Solar Cycle
SIDC-team, World Data Center for the Sunspot Index, Royal Observatory of Belgium,
Monthly Report on the International Sunspot Number,
online catalogue of the sunspot index: http://www.sidc.be/sunspot-data/, ‘1750-2011’