Raw Data Bombshell: no change in Very Hot Days in Australia since World War I

What an absolute bombshell. The original data at 60 of the oldest sites across Australia shows there are no more Very Hot Days now than there were early last century. That’s no trend in 40+ C days for 100 years!

After we were shocked at the latest ACORN changes to our Very Hot Days data, I asked Chris Gillham if we could see the effect of Bureau of Meteorology changes to the original raw data – and he replied it would be too time-consuming writing the code to calculate 40C+ days among the millions of daily temperatures from 112 weather stations across Australia since 1910. Then he did it anyway.

Wow. In 2011, the BoM’s ACORN 1 adjustments wiped out some of the “very hot days” recorded at weather stations in the early 1900s. These were records that had stood for a whole century. Then, quietly six years later, the ACORN 2 readjustments turned the statistical air conditioner on again and cooled people from 100 years in the future.

It’s all especially miraculous given that even the old World War I data was recorded in official BoM-approved Stevenson screens. The BoM won’t consider pre 1910 data because it wasn’t standardized, but even […]