On April 23/24, 2012 Earth experienced a G=3 geomagnetic storm. The Kp index, a measure of magnetic field, peaked at 6.33 out of a maximum of 9. The result of this disturbance created this Aurora event.
It was a beautiful spring night on the Alberta prairies. Temperatures were steady at 16 deg C with very light winds. As you can see there was some cloud cover, but I was able to get far enough away from it to still get a great view of the show.