The Murray Darling Basin just had one of its driest two-year periods on record.

A special climate statement issued by the Bureau of Meteorology on Tuesday reveals that the Murray Darling Basin only collected 644.7mm of rain between April 2017 and March 2019.

This is the Basin's third lowest total on record during this 24-month period, since record-keeping began back in 1900. The only lower two-year totals for this period were 638.2mm between April 1901 and March 1903 and 626.2mm from April 1918 to March 1920.

The Bureau noted that rainfall during 1903 and 1920 increased as the years progressed, so this current dry spell may break both records if it continues later into 2019.

In addition to the lack of rain, excessively high temperatures exacerbated the drought during the last couple of years, by enhancing evaporation. Both 2017 and 2018 were the hottest years on record for the Murray Darling Basin based on maximum temperatures. This was followed by Australia warmest summer on record between November 2018 and February 2019.

The combination of dry, hot weather and water use practices has lead to record low soil moisture availability in the Murray Darling Basin. The average moisture in the top 100cm of soil between April 2017 and March 2019 was the lowest on record for that period.

The most recent major multi-year dry spell in the Murray Darling Basin occurred between 2001 and 2009, during the Millenium Drought. Unfortunately, water storage levels in the northern Murray Darling Basin are currently lower than any point during the Millenium Drought. Storage levels in the southern Basin could reach levels similar to the Millenium Drought later this year, according to the Bureau.

The full Special Climate Statement can be found on the Bureau of Meteorology's website here: http://www.bom.gov.au/climate/current/statements/