The equinox (around March 20 and September 22) brings us better DX propagation, especially the upper bands. The ten meter band (28000 to 29700 kHz) tends to be at its best near the spring or fall equinox. In fact, the equinoxes are when geomagnetic storms are the strongest. These strong geomagnetic storms can actually be very disruptive to the lower bands, which include 40 meters and 80 meters.

Normally, late spring and early summer is prime time for the 10 meter band, using Sporadic E on 10 meters. The fall season generally isn’t considered the peak season for the band, but propagation does get significantly better before and after the fall equinox. The months of September and October cover the peak of the season.

And the fall equinox brings the right conditions for another science phenomenon, the aurora, also known as the northern lights. “The charged particles originate in the magnetosphere and solar wind and, on Earth, are directed by the Earth’s magnetic field into the atmosphere.”

Thus, we could rightly assume that when propagation is great for the 10 meter band in the fall and spring, the conditions will be optimum for spotting the northern lights. The same rule applies if you happen to own a CB radio and skip conditions suddenly get much better. Just face the north and look for green patches in the night sky, that is, if you live in the northern hemisphere. If you live in the southern hemisphere, “the aurora australis (or the southern lights), has almost identical features to the aurora borealis and changes simultaneously with changes in the northern auroral zone.”