Not in California
Admittedly it doesn't often rain here at all at any time of year, so that's not out of the ordinary (sadly...)
I have always mistakes in English and I've study it way more than Esperanto.
It is not fair
Esperanto estas pli regula kaj pli facila ol angla lingvo. Ankaû, via scio de Esperanto tre helpos vian alian lingvojn.
But, coming from a native English speaker, I can definitely understand you :) and that's all you really need
I live in a very rainy part of Oregon (a rainy state); August is one of about three months we can count on it not raining often.
Where would this be talking about??
I'm from Washington, so I'm in a similar situation. But I spent a week in New Orleans in August one year. Rained buckets every single day. So maybe this sentence is about the South.
Ne en ajna ŝtato okcidente de la Rokmontaro...
I think the sentence should be changed to May not August.