Thousands of people are expected at the southern lawns where President Jacob Zuma will be making his address.
But it's not clear whether the rain will have any bearing on the number of people who turn up for the event. All roads leading to the Union Buildings including Church and Vermeleun streets have been closed off while a heavy police contingent is manning the area.
Several marques have been set up at the venue while umbrellas were also being distributed to protect people from the rain.
Those who have arrived are being entertained by various cultural groups from around Pretoria.
A few school pupils carrying South African flags have braved the cold weather to be among those who want to witness the activities that mark the country's 16th year into democracy.
15-year-old Lerato Mokoena from Atridgeville was only a toddler when millions of South Africans went out to vote for the first time on 27April 1994. But for Lerato, like many other so called "born frees" across the country, the important thing is growing up in a free South Africa. "My mother tells me that white people used to fight with black people and that black people were not allowed to vote," said a shy looking Lerato.
So what does it mean for her to grow up in a free South Africa? "Its nice because we are free to do everything we want we can go to any school and people live together," she said. Lerato can sing the National Anthem word for word from beginning to end with minor errors on Afrikaans part but she is working on it.
Freedom Day is an official ceremonial event and thus festivities will also include a performance by the military band, a gun salute followed by a fly pass.
Meanwhile, Director General in the Presidency Vusi Mavimbela earlier said it was all systems go for the awarding of the National Orders taking place tonight.
President Zuma will honour 32 outstanding individuals in the fields of arts, music, Science and those who have made a contribution towards a free and democratic South Africa.
The Order of the Companions of Oliver Tambo, which is reserved for people who are non-South Africans, will be awarded to Cameroonian football boss Issa Hayatou for his contribution to the development of football in SA.
Other recipients include the late ANC stalwart Harry Gwala, paralympian Ernst van Dyk and musicians Jonas Gwangwa and Hugh Masekela. - BuaNews
