Ironically, for wanting to point out these mistakes, Brakey hasn't quite done his homework and picked his own bouquet of oopsie-daisies.
I won't waste too much time in addressing some of the silliness in his post, such as him for some reason pointing out the 2015 monthly temperatures to date are very cold, as if one or two points will reverse the trend in the data that he's allegedly complaining against (there, finished with that part); but I will address his "shocker!" find, that the Southern Interior climate division in Maine is colder than the Northern climate division, even though it is further south, i.e. closer to the equator and more coastal.
Double checking this allegation is rather easy to do: we can go to NOAA's US climate data pages and graph out (or simply download as I did) the average annual temperature for the Southern Interior climate division, and the Northern climate division. The Southern Interior is warmer.
Brakey is correct that the Southern Interior climate division has a average higher HDD count than the state as a whole, according to NOAA. That would make it seem like southern portion is colder on average than the rest of the state. Since the Northern climate division is pretty large, Brakey extrapolates this to conclude that the Southern Interior is colder than the Northern climate division.
But the average (from 1895-2015) HDD for the Northern climate division is 9845 ˚Df, and the average for the Southern Interior is 8381 ˚Df.
The statewide average includes the HDD count from the warm Coastal climate division as well—but it's such a small division, how could that have such a strong impact? Well that's because most of the people in Maine live on the coast or just inland from it, and NOAA weighs the regions by population density to better represent energy usage:
2. State, Regional, and National Data
Degree days are estimated for State climate divisions and then population weighted to more accurately reflect temperature-related energy consumption at the State, regional, and national levels.