it's not a myth....I've been there and seen it. Fire weather is bound to the summer season for it's peak, thus areas that are likely to get it get more of it during the summer months. In the same way, Auroras are bound to the solstices. You can almost guarantee to find light around the equinoxes (I would find it in Qufim during March's cycle almost like clockwork for light clusters when I was leveling crafts with them). The other two seasonal changes are slimmer, but still somewhat reliable.