When are fuel prices going to start to drop

Forever it seemed gas prices were higher in the summer, lower in the winter. Where I live pump premium has been right around $4 a gallon for like 6 months now. Surely I thought after Labor Day prices will go down 20--40 cents, nope. There has been a few days that gas was $3.75 but only a few and then right back up to $4.04 a gallon.

What is going on?