The rand rallied to its firmest since 26 April, scaling 13.1575 per dollar in afternoon trading, before paring gains to 1.35% at 13.1700 by 1629 GMT.
The greenback retreated as the New York Federal Reserve's barometer on business activity in the state unexpectedly fell in May, sinking into negative territory for the first time since October, and following weak data on Friday.
A missile test by North Korea over the weekend also weighed on sentiment, allowing emerging market currencies to gain against the greenback.
