I get the following results:
The Max, Min, Mean and Stdev stats are based on the last 59 years of data by month and are the numbers of hours of sun reported.
First, the good news. The year started well with fairly average Jan and Feb - Jan was actually quite good, but offset by a slower Feb. March and April were excellent, with April the 7th sunniest in the 59 year sample. April, it turned out was to be the sunniest of the year and my generation statistics back that up.
And then the averages started to bite. May, June and July were ok - but very average. I hope to have at least one monster month each summer when the sun comes out to play and stays there. In 2015 this did not happen, I suppose we were paying for April.
And then, the rot really set in. August was unseasonably dull the 55th sunniest out of 59 - pretty close to the bottom. Then September, which can often be a great month was dull and 57th out of 59. October was closer to average but without making a big contribution.
And then November. What can I say? The least sunny November in 59 years with only 41% of the average for the month, my lowest ever solar panel performance on record (in terms of % against model) and a grey 30-day period that never seemed to do anything. At least it kept unseasonably warm which kept the heating bills down.
Thankfully December was a little better and actually produced more kWh than November. But still there were too many dull days.
Overall the year was not that sunny (45th out of 59) and 7% down on the average. Thankfully this was enough to hit the annual target. Although as expected not as much as the previous years.
Hopefully 2016 will be a bit better.
