Mystery black-box method used to make *all new* Australian “hottest” ever records

JoNova (Australia)
"This summer the Bureau of Meteorology (BOM) invented a whole new metric to measure average national heat, which might be all very well except no-one (other than the BOM) seems to know what it is. On January 7th the BOM claimed Australia set a new “average maximum daily temperature record”. Now the headlines are about the “hottest” Australian summer. With both records, no one outside the BOM team has access to the methods or data. This post is about the new “daily” temperature of Australia used to declare Jan 7th was a record, but the same point applies to the “hottest summer” records, even though they may be a different data set. Where is the data? Where are the methods? Is the BOM a science agency or a PR bureau?"