Residential heating oil prices are closely related to the price of crude oil - this is after all what it is derived from. In fact official figures suggest that forty two percent of the price is what the crude oil cost in the first place. Around 12% of the remaining price is what the refining cost. The 46% left over is down to marketing and distribution, plus some profit for the heating oil suppliers.
So a lot of the home heating oil price relates to how it gets to your home. This explains why some may pay more than others - if you live in a remote place for example (and you are probably used to paying a premium for plenty of things).
But the current prices for heating oil are affected by both the price of crude and the time of year. Oil heating systems in the home really only work much during the winter season, and the price can rise during this time. Particularly if there is a cold spell.
The reason for the rise in the these prices is because of this seasonal demand. The refiners cannot easily pick up production since heating oil is only one of the products made from crude oil. If they produce a lot more then they will need to produce much more of the related products too. There is some stockpiling during the summer months, but this is not hugely economical either!
If home heating oil storage tanks were big enough to span the whole winter season then you could fill them up at whatever time you fancied during the year. Unfortunately this is really not sensible - you would need something five times the size of your current tank - it would cost a fortune to install!