Australia just had its warmest financial year on record based on maximum temperatures.

The average maximum temperature in Australia during the 2017/18 financial year was nearly 1.5 degrees above the long-term average. Minimum temperatures were also in the top 10 warmest on record, with data dating back to 1910.

Financial year mean temperature anomaly in Australia. Source: BoM

Combining minimums and maximums during the last 12 months, Australia's mean temperature during the 2017/18 financial year was the second highest on record, behind the same period in 2015/16.

Traditionally, annual climate information has been compiled at the end of each calendar year in Australia. For example, the latest annual climate statement issued by the Bureau of Meteorology states that 2017 as a whole was Australia's third warmest calendar year on record based on mean temperature. The warmest year on record was 2013 and 1917 was the coolest.

It may seem arbitrary to stray from the calendar year and measure Australia's climate during the financial year, which is an economic time scale. However, it's actually quite useful in a number of ways.

The financial year nicely encapsulate some of Australia's main climate drivers, including the typical cycles of El Nino and La Nina events. Another gain is that the financial year includes an entire summer in the southern hemisphere, although this is at the expense of a complete winter. The financial year also contains the whole wet season and tropical cyclone seasons in northern Australia.

When assessing the state of Australia's climate, using different timescales can help separate the background signal of climate change from other influences like El Nino and La Nina.

You can find out more about climate change in Australia here: https://www.climatechangeinaustralia.gov.au/en/