In the past, there's usually 2 FLs per year on Kaiser server, one between september-january and one from febuary-june(ish).
Between June and September, fleet wars and other large events usually happen instead of a FL.
Since the FL started quite late this year (Late October/Early November), and was the longest running season (that lasted until recently), I don't think there might be another season of FL until the fall season. Now, this is upto TNF, as I'm no longer in control of the Kaiser FL. I would rather have a fleet war based summer though, as I will be traveling during the summer, and I'm sure there are others who will likely miss many weekends during FL times.