Good question.  Its kinda complicated, with a few things that matter:

First up is how big the transaction is and, if it requires more space in the block, so miners want a bigger tip.

Theres also how fast you wanna move your coins.  You in a hurry? You can pay extra so the miners push your payment to the front of the line.  Gets it in the next block coming up.   

And heres the tricky one - how congested the whole network is.  More folks moving coins at once fees climb up.  Miners get flooded and can take the highest bidders.

So no crystal ball for future fees.  Too many moving pieces.  Network traffic jams are hard to predict.  But those are the basics - size, speed, congestion.  Thats the recipe behind transaction fees.