daytime and evening temperatures in Tahiti, as well as throughout French Polynesia, are incredibly stable from month to month. You'll observe on the temperature chart below that each day of the year is almost identical to each other day. Moorea Island is only 9 miles (17 km) away, so the climate and weather are basically identical, and there are better Moorea overwater bungalow resorts to consider as well.
Better yet, these averages are so reliable in the tropics that there is honestly little point in checking the forecast in the days before your trip. The record highs ever recorded are only a tiny bit above the average, and it's the same story with the record lows.
For helpful climate information see below the temperature chart