Added 6/8/15: Wood for Trees has been updated, per a comment below. The developer and maintainer asks that, if you like WFT, you consider leaving a tip here:
A lot of people like linking to graphs on Wood for Trees, for plots like the one at the right.
Except WFT is using some bad data.
Here are the raw data used to make the chart on the right.
The problem is, these data only go up to decimal date 2014.5, when the current HadCRUT4 data goes up to March 2015.
Second of all, their anomalies aren't current. Here are their first three data points for the graph at right, starting in 2010:
Here are the actual current first three data points they should be using:
The WFT raw data output says their data comes from http://www.metoffice.gov.uk/hadobs/hadcrut4/data/download.html . Problem is, right now that page returns "Not Found."
So where is WTF getting their data? And why isn't it current?
Then there's the small problem of their decimal dates. For January 2010, for example, they should be using the mid-point of the month, instead of the beginning.
So in the list up above, "2010" should actually be, for January (month=1) of that year, 2010 + (1-0.5)/12 = 2010.042. It's a small error, but it's still an error -- it will lead to end-point errors.
I have never really trusted Wood for Trees, and never cite it. (I prefer to download the data and calculate for myself.) For example, their Credits page doesn't specify which version of UAH they are using, though its seems at most to be v5.6, when UAH is now on v6.0beta2. Perhaps they are waiting to see if that version persists, but not long ago I noticed WFT offering UAH v5.5 when v5.6 had been out for awhile.
Wood fore Trees is a good idea. But it doesn't look to be maintained or current. And, as the above shows, it's not even clear where it's getting its data from.
If someone quotes you something from WFT, be skeptical, and double check what data it's using.