Heatwave conditions are expected to persist over the eastern parts of the North West province and Gauteng until Tuesday.
The South African Weather Service said this will result in high temperatures over and above the average maximum, spreading to the central and northern parts of the Free State.
Saws said it will be hot in central and eastern parts of the country on Monday and Tuesday, with isolated thundershowers expected over the central and south-eastern regions while a cold snap is expected along the south coast, bringing cool and windy weather.
Meanwhile, Saws said November recorded some of the hottest days in the year, breaking records.
The forecaster said hot conditions reached their peak on November 27 when extremely hot conditions were experienced in large parts of the country.
"Preliminary data indicates new temperature records for November over the Northern Cape, Free State and North West provinces. More than 10 stations recorded the highest temperature records on the 27th, with the Automatic Weather Stations at Augrabies Falls recording the highest maximum temperature of 46.7°C breaking its previous record of 46.2°C in 2019. It must be noted that the highest maximum temperature record for Augrabies Falls remains at 48.6°C measured in 2016 and the 46.7°C is the new record for the month of November.
Saws said weather extremes will continue to occur from time to time during the summer season as much as drier conditions are expected.
The forecaster said caution is advised as the El Niño effect might still manifest its influence in the next few months and change the outlook of the rainfall forecast for mid and late Summer.
"Minimum and maximum temperatures are expected to be mostly above-normal countrywide for the forecast period.