I have so many climate programs on the go that I often don’t stop to compare the results from one with the results from another, and so it is between the temperatures from the gridded monthly data and those from the Central England series both of which you can freely download from the UKMO as I do. So what I thought I would do is produce two graphs of 12 month moving mean temperatures from both for the last 30 years and compare them. As you can see they look almost identical if not in overall magnitude but in the shape of the graph. The lower graph of gridded UK 12 month mean temperatures is around a degree colder through the year than that from the 12 month mean CET temperatures. I wager that if you have your own weather station that a graph of your monthly mean temperatures in recent years will be almost identical to the shape of this graph. Because these values are a 12 month moving average, all the short lived warm and cold spells have all been smoothed out and it’s impossible to pick out individual cold or hot spells, although you can pick out the cold winter of 2010-11 which in reality was the result of lower than average temperatures over a much longer period than just those of December 2010. The linear trend shows how fast each series has been warming and although the CET series has warmed by over 0.21°C per decade in the last 30 years the UK gridded series its been much lower at 0.14°C per decade. It’s lower because the UK values are for a much larger area, and at a guess by slower warming across coastal areas to the north and west that fringe the North Atlantic and less continental.