Chris Gillham has completed re-digitizing one years worth of the daily temperature records for Perth in 1940 (perth-1940-actual-raw). These are digitised for all of 1940 at Perth Regional Office 9034 from temperatures published in The West Australian newspaper.
While the majority of the temperatures agree with contemporary BoM data, up to a third of the temperatures in some months disagreed, sometimes by over 1C! This is a very strange pattern of errors, and difficult to explain.
I will be doing more detailed analysis, but Chris reports that overall, the annual average of actual daily Perth max temperatures in 1940, as published in the newspaper, was the same as the BoM raw daily max. The annual average of newspaper daily min temperatures was .3C warmer than in the BoM raw daily min. ACORN max interpreted 1940 as 1.3C warmer than both actual newspaper max and BoM raw max, with ACORN min 1.5C cooler than actual newspaper min and 1.2C cooler than BoM raw min.
Anything above a .1C newspaper/raw difference is highlighted.
It took a couple of days wading through about 310 newspapers to find all the weather reports and although it would be great to have all years from all locations (those with decimalised F newspaper sources) to confirm the Perth 1940 results, it’s a huge task. It would certainly be easier if the BoM just provided the temps from the old logbooks.