Darwin's Dry Wet Season

Joel Pippard, 28 April 2019

With the end of April comes the end of the official wet season for Australia’s northernmost capital, and it had been quite a dry one.

Darwin has recorded 1170mm of rain in its gauge from October 2018 until 9am Sunday 28th April, about 69% of average. This makes it the seventh driest wet season and the third driest of non-El Niño years in their 77 years of records.

This rainfall was also 833mm shy of what was recorded in the 2017/2018 wet season and a mammoth 1314mm short of the 2016/2017 season. In fact, rainfall was quite close to the 2015/2016 season that saw 1119mm fall. That year was under the influence of one of the strongest El Niño events on record.

This season was mainly dry due to the very late onset of the monsoon, arriving about 5 weeks later than usual on January 23rd and 2 days shy of the latest onset on record. Even with the late onset, when the monsoon was over Australia, it directed moisture more towards Queensland, making Darwin miss out on most of the rain it would normally receive from January to March.

Darwin is now starting to move into the cold-dry season, typically running from May to August. During this time, it is not unusual to see rainfall in the single digits (or even no rainfall) each month. However, a weak low pressure system developing mid-week may provide some showers or storms to top up the dams before the conditions become much drier.