Month names collection / metastudy

[Koen G]

I agree with the general sentiment that Octembre points to the northern French dialects. North of Paris, basically. 

I would say that the "g" in augst is still remarkable. Germanic influence? Places like Hainaut also got correspondence in Flemish. And I presume a city like Metz, where Octembre is also found, mixed French and Germanic influences as well.