December 2019 was the driest December on record for Australia. Rainfall deficiencies expanded and
intensified with the area of lowest on record rainfall for some periods growing over eastern
It was the third-driest December on record for Victoria. Eastern and most of western Victoria
recorded very little rain, with large areas receiving less than 10 mm for the whole month. It came of
the back of close-to-average rainfall for most of the State in November which followed a very dry
October (8th driest on record).
2019 was bookended by very warm days for Victoria—the warmest January and the second warmest
December mean maximum temperatures on record. Statewide, the monthly mean maximum
temperature was 3.13 °C warmer than the long-term December average. While mean maximum
temperatures for December were much warmer than average across most of Victoria, in the north
they were highest on record, compounding the moisture stress.
The long-term rainfall deficiencies combined with the high temperatures were two factors increasing
the risk of bushfire. In addition to fires still burning from earlier ignitions, a number of significant
new fires commenced in East Gippsland during December. All of Victoria recorded accumulated
Forest Fire Danger Index values for December in the highest 10% of historical records, and the
highest on record for December over the north and northwest of the State and in East Gippsland.
The Forest Fire Danger Index is one common measure of fire weather conditions. Rainfall influences
the dryness of fuels and is a key factor in calculating indices for determining fire weather risk such as
the Forest Fire Danger Index.
Dry soil conditions continued across much of Australia, including Victoria, through December.
Month-to-date root zone soil moisture is close to lowest on record for much of East Gippsland and
very much below average for the northeast.
Rainfall deficiencies over the last three years are very deep—there are large areas of lowest on
record rainfall over southeast Australia— due to the prolonged nature of the current dry period.
Rainfall has been below average in most months over much of the country since early 2017.
Consistent, widespread, above average rainfall over several months will be needed to lift areas out
of deficiency and provide relief from the dry impacts (such as renewing water storages).
See more details in the Bureau's latest drought report.