While the northern hemisphere is experiencing a record drought, the southern hemisphere is breaking century-old records with massive rainfalls. July 2022 set the Sydney record for the wettest July in 164 years mid-way through the month reaching 342 mm (13.5 in.) by July 14th. By the end of July a total of 404 mm (15.9 in.) of rain had fallen which is more than four times the average for July in Sydney.
Sydney, capital of the state of New South Wales on the east coast of Australia, has been hit by strong rain falls all year, with February measuring 2-3 times average rain falls and devastating flash flooding in many lower lying areas. The La Niña weather phenomenon has been causing record weather patterns all over the globe and is expected to continue wreaking havoc on both sides of the globe, with heat waves and droughts in the northern hemisphere and rain storms and flooding in the southern hemisphere expected to continue well into 2023.
The Australian Bureau of Meteorology (“BOM”) officially declared a negative Indian Ocean Dipole (“IOD”) on August 2nd. A negative IOD happens when westerly winds bring warmer waters near Australia. This sets up a temperature difference across the tropical Indian Ocean, with warmer water in the east and cooler in the west, resulting in excess moisture flowing to Australia. A La Niña year coupled with a negative IOD typically brings heavy rains and flooding to Australia, especially the east coast.
You can be on whichever side of the climate change debate you want, but the below chart by meteorologist Ben Domensino from Weatherzone illustrates how unique of an outlier the recent rainfall Downunder has been. Australia is typically better known for heat waves and bushfires but the current negative IOD combined with La Niña has been causing century-old-record-breaking rains and floods, resulting in dams breaking and, even more tragic, loss of lives.
This year has been phenomenal in #Sydney. The city has now broken two monthly rainfall records in 2022 (March and July), bringing its cumulative annual total up to 1951.4 mm at the end of July. This is by far Sydney’s wettest year-to-date in records dating back to 1859. pic.twitter.com/WsnEWQk6BN
— Ben Domensino (@Ben_Domensino) August 1, 2022