Historical difficulty has no effect on future difficulty, to the extent that using history to suggest what will happen in the future would be far from accurate.

Some people like to say there is a hard link between price and difficulty.
Clearly the past few months have proven how wrong they all are

There are a number of factors involved, and most of them cannot be predicted with any accuracy:
1) Availability of new miners
2) Electric price
3) Electric availability (e.g. in china there are seasons each year)
4) BTC Price
5) Availability of old miners to simply be turned back on
6) Availability of old miners for sale at reasonable prices
7) Scam price of old miners - and those stupid enough to pay them

No doubt some can come up with more factors.

Two of the above have their own whole random list of things that affect them
1) and 4)

Alas the only thing you can guarantee, is that BTC price and difficulty will go up, down and sideways, but with a long term trend of going up.