Brazil trip late March/early April - Weather

Hi! I booked a trip to Brazil from March 21st to April 5th, with this program:

Rio from 3/21 - 3/27

Itacare from 3/27 - 4/2

Sao Paulo from 4/2 - 4/5

I wanted to have enough time in Rio to enjoy the vibe of the city at my pace. For Itacare, I want to spend my time at the beach surfing (beginner), chill in the pousada and try all the food. For Sao Paulo, visit museums, art galleries etc...

Now my concern is the weather... It's only after booking the trip that I found out that late March/April was the beginning of the rain season and I'm afraid it might ruin the experience, especially in Itacare.

I don't mind if there are heavy but quick bursts of rain everyday, but if it's cloudy and raining all the time that will be annoying.

Do you know how the weather generally is during that period in these 3 locations? Should I keep my plan as is or should I find another beach town in another region with less rain? Should I visit Brazil during another time of the year (that would mean waiting at least one year as I already have trips planned this year)?

Thank you for your help!