About the Temperature Timeseries Graphs

Analyses available

Australian and regional temperature timeseries are available from 1910 for annual mean temperatures, but only from 1950 for monthly and seasonal mean temperatures. This is because the dataset on which the annual analyses are based starts in 1910 (prior to this date Australian temperature records are sparse and some are measured in non-standard ways). Monthly and seasonal temperature analyses are limited to the post-1950 era because they are based on a daily temperature dataset and there is currently only a limited amount of digitised daily temperature data prior to 1950. The average of the monthly anomalies for any given year will not necessarily be exactly the same as the value determined from the high-quality annual temperature dataset because the monthly timeseries are based on a different dataset.

Note that temperature timeseries are presented as anomalies or departures from the 1961-1990 average because temperature anomalies tend to be more consistent throughout wide areas than actual temperatures. Normal values (1961-1990 averages) are provided for the selected variable and region. 1961 to 1990 is the current international standard period for the calculation of climate normals.

Separate timeseries are available for maximum, mean and minimum temperature, as well as diurnal temperature range (DTR). Mean temperatures are the simple average of the maximum and minimum temperatures, while DTR represents the difference between maximum and minimum temperatures.

Mean temperature values are provided for each of the seven major Australian states and territories, all of Australia, and six climatologically distinct regions; northern Australia (north of 26°S), southern Australia (south of 26°S), southwestern Australia (southwest of the line joining 30°S, 115°E and 35°S,120°E), southeastern Australia (south of 33°S, east of 135°E), eastern Australia (QLD, NSW, Victoria and Tasmania), and the Murray Darling catchment. Values calculated for NSW include the Australian Capital Territory.

Timeseries are determined for each Australian state, the Northern Territory and the six regions shown above

Data used

The temperature timeseries are calculated from homogeneous or "high-quality" temperature datasets developed for monitoring long-term temperature trends and variability (see maps below). Where possible, each station record in these datasets has been corrected for data "jumps" or artificial discontinuities caused by changes in observation site location, exposure, instrumentation or observation procedure. This involves identifying and correcting data problems using statistical techniques, visual checks and station history information or "metadata".

Please note that any use of these data should be acknowledged to the Bureau of Meteorology. Apart from the purposes of study, research, criticism and review, no part of these data may be reproduced, or redistributed for any commercial purposes, or distributed to a third party for such purpose, without written permission from the Director of Meteorology.

The actual data values used to produce each graph is available via the "Raw Data Set" link. The format for these data is:

    <start year><start month><end year><end month>   <mean temperature anomaly (°C)>

The "Sorted Data Set" link provides the timeseries as a sorted list in order to place recent values in historical context.

Locations of records included in Australia's high-quality annual temperature dataset

Locations of records included in Australia's high-quality daily temperature dataset

Further information

Della-Marta, P.M., Collins, D.A. and Braganza, K. 2004. Updating Australia's high-quality annual temperature dataset. Australian Meteorological Magazine, 53, 75-93.

Jones, D.A. and Trewin, B.C. 2000. The spatial structure of monthly temperature anomalies over Australia. Australian Meteorological Magazine, 49, 261-276.

Jones, D.A. and Trewin, B.C. 2002. On the adequacy of digitised historical Australian daily temperature data for climate monitoring. Australian Meteorological Magazine, 51, 237-250.

Torok, S.J. and Nicholls, N. 1996. A historical annual temperature dataset for Australia. Australian Meteorological Magazine, 45, 251-260.

Trewin, B.C. 2001. Extreme temperature events in Australia. PhD Thesis, School of Earth Sciences, University of Melbourne, Australia.

Full electronic copies of papers published in the Australian Meteorological Magazine, now known as the Australian Meteorological and Oceanographic Journal, are available online.