The lowest water temperature (78° F) in Punta Cana occurs in March, the highest (85° F) in September. The climate in Punta Cana in July is still a mix of hot and sunny days, interrupted by intense but brief tropical rains. It's difficult to predict, but assuming that one disturbance per year affects Punta Cana, usually between 2 and 3 days, and that the hurricane season officially lasts 180 days, it's likely to be affected by bad weather and some heavy rains. In April, the weather in Punta Cana remains favorable for a carefree vacation and enough beach time without interruptions due to rain.
Rain in Punta Cana is part of the climate, but there are usually 2 to 3 heavy showers (often at night), and in the meantime, you can enjoy the perfect Caribbean weather with lots of sun. Using them, you can check the water temperature in Punta Cana on any day of this period that interests you. This is because, firstly, the weather in Punta Cana and throughout the Caribbean is completely different and difficult to predict and, secondly, if it only rains one drop a day, the weather app marks this day as a rainy day. While sea temperatures in Punta Cana are as accurate as current data allow, there may be slight local and regional variations depending on conditions and variations in sea depth.
It's common to have a few showers at any time of the year in the Dominican Republic, but you can expect at least 70 to 80% sunshine while enjoying your vacation in Punta Cana on its beautiful beaches. As in the rainy season, the hurricane season in Punta Cana (and in the Dominican Republic) lasts from June to November. That's why, in my opinion, Punta Cana and the Dominican Republic are an excellent tourist destination all year round. So, it doesn't matter if it's the rainy season in Punta Cana or the dry season, it won't rain all day long.
The TSM is a measure that provides information on global climate and can be used to predict the climate in Punta Cana, as well as for simulations of atmospheric models and to study marine ecosystems in the area. Depending on the humidity, the sun, the wind and your personal feeling, temperatures in Punta Cana can appear and feel as high as 100° F.