The heaviest rain in decades pounded much of central and western Argentina on Tuesday, prompting evacuations, even as wildfires roared across much of the parched far south.

Rain has been heaviest in the provinces of Cordoba, San Luis, Santiago del Estero and Santa Fe's capital city of the same name, forecasters said.

In the central-western region, "this is the worst weather disaster we have seen in the past 50 years," said Cordoba governor Jose Manuel de la Sota.

His province alone has seen at least seven people killed and 1,000 evacuated in the past two weeks.

In San Luis province "there are families who have lost everything," said Facundo Dominguez, mayor of Concaran.

The southern Patagonia region, however, is dry and in some cases forests are ablaze.

At least 34,000 hectares (84,000 acres) of forest have already been destroyed by the flames, which started two weeks ago in the Cholila lake region, according to national fire management chief Fernando Epele.

Local authorities first said lightning triggered the fires. But federal officials have said arson cannot be ruled out in some cases of potential "burn and rebuild" land speculation.