How heavy is the rain in the Dominican Republic?

I'll be in the Dominican Republic in July for 2 weeks. Flying into Santo Domingo and leaving out of POP. As far as I know, i'll be up near the mountains. What is the rain like there? Is it heavy? I bought a waterproof rain jacket but I was wondering if I should also get rain paints? Are they necessary? I need to save money but at the same time, I don't want to get wet and I have a lot of knowledge in travel/sport clothing so I don't like to buy poor quality products either.