This is one of the many “adjustments” I found had been done to temperature data.

“The Australian Bureau of Meteorology declared 2013 the hottest year on record.”

But we find out later (graph below) that they took a cooling trend (blue) and turned it into a warming trend (red) …

“…This is significant. The Bureau now admits that it changes the temperature series and quite dramatically through the process of homogenisation*.

I repeat the Bureau has not disputed the figures. The Bureau admits that the data is remodelled*.”

http://jennifermarohasy.com/2014/08/heat-is-on-over-weather-bureau-homogenising-temperature-records/

*Those are just two examples of the way they spell in Britain and Australia.  Many non-English-speaking countries adopt the same for their English writing.  I put up with that for 17 years while working for a Norwegian Company -Steve