ここでは天気は変わりやすい。

here (place physically close to the speaker, place pointed by the speaker while explaining); this place; these last (followed by a duration noun and a past sentence: time period before the present time of the speaker); these next ... (followed by a duration noun and a non past sentence: time period after the present time of the speaker); the next ...

indicates location of action; at; in; indicates time of action; indicates means of action; cause of effect; by; and then; so; indicates continuing action; indicates certainty, emphasis, etc.

topic marker particle; indicates contrast with another option (stated or unstated); adds emphasis

weather; the elements; fair weather; fine weather

to change; to be transformed; to be altered; to vary; to move to; to be different; to be uncommon; to be unusual

easy; likely to ..., have a tendency to ...; easy to ...