Johannesburg - With winter weather settling in, motorists must brace for huge increases in fuel prices on Wednesday, with petrol to rise by 52 cents a litre and diesel by 76 cents a litre.

The Department of Energy said the June prices were because of a general increase in the prices of petroleum products internationally and the weakening of the rand to the dollar.

The rand's value relative to the dollar contributed to the price adjustments by more than 20c a litre, the department said.

The increase in diesel prices can be attributed to the fact that refineries will be producing more petrol for the summer season in Europe.

Illuminating paraffin will also increase by 83c a litre and liquefied petroleum gas by 98c a kilogram.

The latest increases are the largest rises since April, when petrol prices jumped an average of 87c a litre and diesel by almost R1 a litre.

Although fuel prices, particularly diesel prices, decreased substantially at the beginning of the year, prices jumped dramatically in April.

Last month saw a small increase in petrol prices and decrease in diesel and other fuel prices, with increases across the board this month.

The Automobile Association said last week that oil prices have been increasing since late April because of output reductions in Colombia, the US and Nigeria.

“With South Africa's weak economy, our concern is that even if oil prices moderate, further declines in the rand will mask the benefit,” the AA said.