The rand weakened from below R8.80 against the dollar to R9 on Monday.
A slump in mining exports and rand weakness also contributed to this.
A statement released by the South African Revenue Service on Thursday said the trade deficit had grown to R24.5-billion last month compared to R2.7-billion in December. It was R21.1-billion in October.
The value of exports fell by 1.3 % compared to January 2012 on weak shipments of "precious and semi-precious stones", "machinery and electrical appliances", as well as "vehicles, aircraft and vessels".
Imports, on the other hand, were up by 15.3% on the import of "machinery and electrical appliances", "products of the chemicals or allied industries", "original equipment components", and "base metals and articles thereof".
Investec chief economist Annabel Bishop said that while it was not unusual to see a slump in exports in January, as the year takes off slowly, the data also reflects the global slowdown that is now impacting on the South African economy.
“Export contracts are set many months previously and so are typically reflective of economic conditions in this earlier period,” she said.
Demand predicted to improve
“Demand for South African exports are expected to improve from the middle of 2013 on improved global growth. Caution should be taken, however, as the trade figures will not strengthen initially. There can be a lag between rising global demand and the impact on the physical quantity of exported goods of up to three months.”
The current-account gap will average 6.2% of gross domestic product in the next three years – higher than the 5.6% originally estimated by treasury.
Foreign investment in stocks and bonds is used to finance shortfall.
Bishop said foreigners became strong net purchasers of South African equities in January, purchasing R2.6-billion, and R1.8-billion worth of gilts in the final days of the month.
February shows foreign purchase of R4.9-billion of gilts and R7-billion of equities to date.
South Africa’s 2013 budget was slightly negative from a sovereign credit ratings perspective as the deficit and debt ratios (to GDP) widened, with the rand weakening consequently.