Snow has closed part of the Lootsberg Pass between Middelburg and Graaff-Reinet, and the Wapadsberg Pass between Cradock and Graaff-Reinet on Saturday, the Eastern Cape traffic spokesperson said.
"Luckily we closed the pass in good time so nobody could get stuck," Charles Bramwell, deputy provincial director for traffic in the Eastern Cape told News24.
He said vehicles are being diverted and nobody seemed to be in distress.
Motorists should heed warnings by authorities as the situation is monitored.
This was in line with a weather alert predicting cold conditions into the weekend with flood warnings in some parts of the country and thunderstorms, gale-force winds and snow in other parts on Saturday.
Bramwell said that a tree also fell on to the R102 near the N2 between Humansdorp and Stormsrivier during heavy rain so that road was closed while emergency services removed the tree.
George municipality spokesperson Chantel Edwards-Klose said the Potjiesberg Pass between George and Uniondale had been reopened after an earlier closure but motorists should travel with caution.
The Swartbergpass remains closed and flooding to a depthy of 30cm was reported at the Harlem Bridge.
"Vehicles can still cross with caution," she said of the bridge.
Localised flooding was also expected along the coast and adjacent interior between Mossel Bay and Port Alfred, moderating from the west.
Heavy rain leading to flooding was expected over the northeastern parts of KwaZulu-Natal and the extreme eastern parts of Mpumalanga.
Severe afternoon thunderstorms were expected over the eastern high grounds of Mpumalanga and Limpopo.
Disruptive snowfalls were expected over the Swartberg mountains in the Western Cape, the Sneeuberg and the Winterberg and the Tsitsikamma mountains of the Eastern Cape, and the southern parts of the Drakensberg.
Gale force SW winds of 35 Knots were expected between Port Elizabeth and Port Alfred in the early morning.
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