hi Lydia,
welcome to DR1 forum.
to kep you up to date about the real matter of fact weather in Punta cana independant from the forecsting sites, just check in daily on top of thos forum on the sticky named "current weather Punta Cana". we do not predict the weather for long ahead there(aside of god nobody could such, and he did not post, yet), but we write every day at least once how the weather is there actually "really", right now. you can compare such to the forecast you got the prior day for the same day/area, you will be surprised what life hold's of great pos surprises.
for your upcoming visit,
without making a "weather froggy who knows it all",
we have actually since days mostly great sunshine, very low winds from the east around 10 mphr, few clouds around,1-3 very short showers per day in isolated areas(that means most people here do not see any rain, you have to calculate perfectly to find the short showers and get some drops of them).
have a pleasant stay
Mike
