I usually have five or six episodes a year, on average. I'll be symptom-free for a few months and then spend another few months switching between depression and mania (and occasionally a mixed episode because why not, I guess) with no pause. This summer was... odd. I was almost continuously manic save about five weeks of depression interspersed between; usually it's closer to the other way around. My mother wondered if the unusual amount of sunlight and heat we've had in Texas this year doesn't have something to do with it. I'm very sensitive to changes in light and temperature (usually midwinter is the worst time of year for me), and in winter especially the lack of light is a trigger, so I suppose it's possible it works the other way too.