Heavy rains are set to hit Sydney and New South Wales starting Wednesday, with forecasts predicting up to 35 millimeters of rain on that day alone.

A low-pressure system moving from South Australia will bring a persistent rainband to the eastern coast, leading to further rain accumulation throughout the weekend.

Meteorologist Rob Sharpe has indicated that Saturday, August 2, 2025, could be particularly wet, with some areas potentially receiving up to 100 millimeters of rain.

Regions such as Sydney, Newcastle, and Wollongong are expected to be the most affected, with rain totals between 20 to 50 millimeters anticipated over the weekend.

The Bureau of Meteorology forecasts that certain areas could see up to 100 millimeters of rain within a 24-hour period, with Sydney facing the most intense rainfall.

Christie Johnson from the Bureau of Meteorology warns of cold, overcast conditions, with air temperatures around 15 degrees Celsius, and a 'feels like' temperature potentially dropping below 10 degrees due to cold southerly winds.

These cold southerly winds will contribute to a chilly feel, with many areas struggling to reach double digits in temperature.

In Sydney, maximum temperatures are projected to only reach 15 degrees Celsius, which is 5 degrees below the average for this time of year.

Other cities across Australia will experience varied weather, with Brisbane expecting a maximum of 24 degrees Celsius, while Canberra will see temperatures only reaching 12 degrees Celsius, accompanied by patches of morning frost.

Weatherzone has indicated a possible negative Indian Ocean Dipole (IOD), which could lead to increased rainfall and cooler conditions in southeastern Australia, with seven models predicting this pattern forming between August and November.

Research suggests that climate change may increase the frequency of hailstorms by 29% in Sydney and Canberra, with larger hailstones becoming more common as the atmosphere warms.