Eastern subterranean termites (Reticulitermes flavipes) typically swarm in the spring and early summer, but they are sometimes seen in the fall when the climate is right. This year the temperature dropped in early November, then warmed up with some rain. Temperatures and humidity between 68 to 72 create the conditions favorable for swarms, between the months of March and November.

As a side note, the HVAC system in a house can create the same environmental conditions. This can also send termites into the swarming mode.

These are pictures of a sizeable outside swarm of Southern subterranean termites (R. Hageni) in the south this past fall.

Images provided by Cory Kirkley on 12/09/2014,
from Vidalia Georgia Orkin Specialist.