hi there,
Dominican Republic has a lovely warm weather so bring mostly shorts, t-shirts and bathing suits for day time. However, do bring smart clothing such as trousers and jackets for when you go out as Dominicans tend to dress more formally specially in a larger
cities.
If you travel to
Dominican Republic in the winter months do bring a couple of warmer items of clothing as night are known to be a little cooler than in summer.
Hope this helps
Vacationbuddy