Andrew Wilkie MP
Member for Clark
188 Collins Street
HOBART TASMANIA 7000
Andrew.wilkie.mp@aph.gov.au

Dear Mr Wilkie
Thank you for your correspondence of 27 August 2026 on behalf of your constituent Thomas
Berger and for providing the Bureau of Meteorology (the bureau) with a copy of Mr Berger’s
analysis on bureau data control.

I would like to thank Mr Berger for the considerable effort involved in identifying and
documenting the anomalies and patterns described in the report. Contributions from members
of the public and the broader scientific and citizen science community play an important role in
supporting discussion and scrutiny of Australia's climate records.

The bureau is committed to maintaining the integrity, quality and transparency of Australia's
meteorological and climate datasets. This includes the careful stewardship and long-term
management of historical observation records, ongoing quality assurance processes, and the
continued publication of data, methodologies and supporting documentation to enable public
access and independent examination.

I note that the report raises a number of matters relating to the bureau's temperature datasets,
including concerns regarding data integrity, instances of apparent data duplication, periods of
missing observations, homogenisation methodologies, and the application of adjustments
within the ACORN-SAT dataset. The report also recommends further investigation of specific
stations and greater transparency around the management and processing of historical
temperature records.

The bureau has examined the report and the underlying data in detail. We have confirmed a
small number of duplicated historical daily temperature records, including four post-1910
months relevant to ACORN-SAT. These account for fewer than 200 daily values from a dataset
containing more than seven million values. The affected records will be flagged and excluded
until the original historical observations can be located and re-digitised. Our assessment is that
they have a negligible effect on Australia's long-term temperature record.
The bureau rejects allegations of fraudulent or deliberate manipulation of Australia's
temperature record - there is no evidence to support this assertion, and it has no basis in fact.
Most of the other matters raised in the report reflect well-documented characteristics of
historical observations, including missing data and changes in recording precision, or
misunderstandings of how ACORN-SAT homogenisation and cumulative adjustments operate.
Importantly, the bureau does not overwrite or delete original temperature observations when
producing ACORN-SAT. Original observations are retained separately, quality issues are
recorded, and ACORN-SAT is produced as an additional analysed dataset. Both original and
homogenised data are made available for external scrutiny. 

Indeed, the analysis provided to you was only possible because the bureau makes the underlying observational data publicly available.

The integrity of ACORN-SAT has also been subjected to repeated independent scrutiny. Its
methods have been published in scientific literature and independently reviewed in 2011, 2015
and 2018, with those reviews expressing overall confidence in the bureau's practices and
method, the development and operation of ACORN-SAT and continued support for the
bureau's approach to homogenisation.

The bureau will correct the identified historical records and continue to maintain the
transparency, independent scrutiny and continuous improvement appropriate for this important
national dataset.

Again, I thank Mr Berger for taking the time to prepare and provide this report. I appreciate his
interest in ensuring the integrity and transparency of Australia's climate and meteorological
records.

Yours sincerely
Dr Stuart Minchin
CEO and Director of Meteorology