Background
The records maps display a range of record and near-record observations at individual stations or analysed across a larger area such as State and Territory or National records for the period September 2012 to March 2013. A number of these observations are cases in which the previous record has been equalled.
These observations highlight noteworthy weather events as well as significant deviations from long-term averages over longer periods. Many of these have been reported in recent Special Climate Statements.
Records are reported at daily, monthly and longer timescales for a range of variables including maximum, mean and minimum temperature, rainfall, sea surface temperature, and other significant metrics such as consecutive days above a temperature threshold or early-season temperature records. There are occurrences of these as both station observations and area-averaged values. The range of observations which are displayed on the map are listed below.
- Consecutive days or nights above or below a temperature threshold;
- Number of days or nights above or below a temperature threshold in a period;
- Highest or lowest temperature (maximum or minimum) for a day or night,
(reported as ‘Warmest or coldest day or night for a period’); - Warmest or coldest temperature (maximum, mean or minimum) averaged over a period;
- Warmest or coldest temperature (maximum, mean or minimum) averaged over a period since X,
(reported as ‘Warmest December average maximum temperature since 1947’ etc.); - Highest or lowest rainfall for a period,
(reported as ‘Driest December’, ‘Wettest day for any month’, etc.); - Highest or lowest rainfall for a period since X,
(reported as ‘First December with 0.0 mm of rainfall since 1947’, ‘Wettest December since 1947’, etc.); - Earliest or latest day or night reaching or failing to reach a temperature threshold;
- Warmest or coldest start to a period (for maximum, mean or minimum temperatures);
- Warmest sea surface temperatures for the Australian region for a period;
Data shown on these maps
The records displayed on these pages are sourced from a non-exhaustive list of station and area records. Several requirements need to be satisfied for records to be included in these pages, as well as passing an assessment of the significance of the event for metrics such as total number of days above a temperature threshold for a period (e.g. the rarity of the event and/or the amount by which the previous record was surpassed).
To be included stations must have had at least 40 years of observations on record. Composite records have been used at some sites to extend the period of observation to meet this requirement where suitable sites are available.
For record-low monthly rainfall totals to be included the station must have had a previous record low rainfall total of more than 0 mm – this is because away from the coast and northern tropics stations recording zero monthly totals are quite common. As multi-month totals of 0 mm for these areas are more meaningful, record low rainfall totals of 0 mm are only reported for longer periods.
Data for these records is sourced from multiple datasets, including:
- raw station observations (quality controlled for gross errors) for daily station records, as provided at Climate Data Online,
- spatially homogenised gridded data (also known as the AWAP dataset) for area averages at daily timescales, consecutive-days records and also for area averaged rainfall,
- temporally homogenised temperature data (the ACORN-SAT dataset) for area averaged temperature at monthly and longer timescales, and
- sea surface temperature data obtained from NOAA
Data shown in these pages has been screened for errors and is subject to ongoing quality control checks. Similarly, our analyses are progressively updated to incorporate this quality control and additional data as it becomes available. Full quality control of real-time data is not completed until some months after any particular weather or climate event, and not all stations report in real-time. Hence, some values presented in these maps may later be updated.
Text of records is generally given using the following information structure:
| rank of record | period | element | region |
|---|---|---|---|
| Equal-warmest | spring | average maximum temperature | for SA |
Definitions
Maximum (highest) and minimum (lowest) temperatures for the previous 24 hours are nominally recorded at 9 am local clock time. Minimum temperature is recorded against the day of observation, and the maximum temperature against the previous day. The mean temperature is obtained by taking the average of the maximum (highest) and minimum (lowest) temperature recorded for a given day.
The average maximum, mean or minimum temperature is the arithmetic average of all daily observations for that element (maximum, mean or minimum) recorded during the period over which the average is taken.
The national daily average temperature is an area-weighted national average of the daily maximum, minimum or mean temperature for a particular day.
Daily rainfall totals record the rain that fell in the 24 hours to 9 am on the day of the observation.
A late season record is the latest a high (low) maximum or minimum temperature has been recorded in the first (second) half of the year. An early season record is the earliest a high (low) maximum or minimum temperature has been recorded in the second (first) half of the year.
The seasons are as follows in the southern hemisphere:
- Spring – the months September, October, November
- Summer – the months December, January, February
- Autumn – the months March, April, May
- Winter – the months June, July, August
