Ubatuba is a municipality on the northern coast of São Paulo state, on the border with the Rio de Janeiro state.
Ubatuba is a true paradisiac area, being predominantly covered by exuberant Atlantic rainforest and containing more than 80 non-contiguous beaches distributed along 100 km of coast. You may find some of them completely deserted, especially on low season.
Ubatuba is devoted to tourism, but the fact that it is relatively far from both São Paulo and Rio de Janeiro (despite being almost exactly between them) makes it far more a "vacation or holiday" destination than a "weekend destination".
For that reason, during summer vacation (Jan-Feb) and holidays, the city and the more central beaches will be packed, and congestion in the Rio-Santos road may frequently occur. However, during the rest of the year, especially during weekdays, the city will be almost empty, and some beaches far from the city center may even be completely deserted.
The low season is thus great if you want tranquility, but in the other hand, the city center will be far less vivid, and it may be very difficult to find something to eat or drink outside it. Many shops, kiosks and restaurants close during low season.