It has always been my ubderstanding that 'earthquake weather' was a function of barometric pressure if it works at all. I believe studies have been done of quakes and the weather at the time of the quake. From October and May many quakes in Souther Cal occure during increased barometric pressure times. Northridge being an example. The weather is generally nice at those times and increased pressure. The pressing of the air column on the surface of Southern Cal was found to actually deform the ground thus the possible mechanism for initiating a quake. Perhaps someone knows of this study or others like it. If I remember correctly, something like 60%of the quakes in Southern Cal happened during these times. Seems high to me.
I am assuming that our "indian summer" type days fall under this scenario. I realize this goes against some information.
Bob in Woodland Hills