Known as the "the city of the sun", Natal sees more than 300 days of sunshine a year. This is where you'll see some of the best stretches of coastline in South America, including good lively city beaches, some with excellent surfing conditions.
Two of the nicest beaches in the area are Ponta Negra bay (10km away), and Pipa beach (80km away). They're truly spectacular.
Also worth a visit is Rio Grande do Norte which has around 40 great beaches. Check out Pirangi, Jacuma, Maracajaú, Galinhos in particular.