Sydney and coastal regions are due for wild weather on Thursday, with heavy rain expected as an arriving cold front meets the remnant tropical low from Cyclone Debbie.

The city can expect 30-45 millimetres of rain on Thursday, with the chance of a thunderstorm in the morning and afternoon, the Bureau of Meteorology said.

Temperatures will sit in a narrow range of 23-26 degrees for the whole day.

The bureau issued a severe weather warning on Wednesday for heavy rainfall and damaging winds for the coastal fringe of NSW from Sydney north to the Queensland border (see chart below).