May be of interest to some of you.
I recently did some calculating and comparison of my heating costs over the past couple of years. The proper way is to use degree days to get a comparison based on temperature, not on time. Mild winter = less fuel of course. This year we are close to normal, but ahead of last year, at least in New England
If you want to do this you can keep track from the weather report in the daily newspaper, but if you need historic data, it will be difficult. From a Google search I found