There are currently no severe weather warnings for the region, but these are likely as the week progresses, the Bureau of Meteorology warns.

Up to 35 millimetres of rain could fall in the Illawarra, with Friday to the be the wettest day.

"While there are very large areas of instability across the country this week, it doesn't mean you're going to get hit everywhere every day," meteorologist Dean Narramore said.

If severe thunderstorms do hit the region, they could bring large hail, damaging winds and heavy rain possible.

Later in the week the weather pattern will move towards Victoria and South Australia.

Bellambi has already recorded more than three times its average November rainfall this month, with 201.2mm. The average for the month is 90.6mm.

Albion Park has been slightly wetter than average, with 83mm of rain recorded so far. This is slightly above the usual 80.8mm.

Kiama has been a little drier, with 88.2mm recorded so far in a month with an average of 89.5mm