Flood warning for Adelaide Hills

A flood warning has been issued for parts of the Adelaide Hills with up to 80mm of rain expected over the next 24 hours.

The Bureau of Meteorology says a low pressure system will deepen over South Australia's southeast on Tuesday night with a band of rain developing across the Mt Lofty Ranges.

The BoM says there's a risk of flash flooding, particularly for areas along the Onkaparinga, Angas and Bremer rivers.