Might be rainy.
Search or just scan the Bay Islands forum posts, you'll see how the weather shakes out.
As you read other threads, you'll see that which side of the island you stay on may affect your diving. Spin-offs from Tropical Storms and Hurricanes that pass to the NW, rarely striking the Bay Islands, but they may cause some serious wind and wave or turbid water.... depending on what area you select.
"...where can i get the most bang for the buck diving? I don't care about the lodging as much as I do the diving?"
It really depends upon what you want. Do you mean to say that you want 2 dives a day? Do you want 3 ? How about 4 ? Are you nuts for night diving?
No one can give you valid suggestions without knowing what your specifications are. If you are wanting at 3 or more dives a day, look carefully at AI Resorts.
October should see some great pricing.