So it turns out that January is about the worst possible month to visit Tahiti as weather goes (temperature, not shown, is also lowest in the US summer months when rainfall is lowest). Conversely, US winter months are the best for the Philippines.
Both get roughly the same amount of rain ("a lot") in their rainy season. (The Tahiti graph is in mm -- 15 inches is about 380 mm, so they peak at about the same rate.)
Rachel has put me in charge of getting passports. ("I'm sure you'll get the job done. Plus, I don't want to deal with it!")