We have just returned from a Far East cruise -, weather in Okinawa, Japan, warmish but raining. In Taiwan,(Keelung), warm but no sun in the northern part, warm and showery in the southern part. Vietnam (Halong Bay area) early 70's southern part mid 70's and at last sun. Sanya in China early 80's and beautiful and the weathern stayed like that for the return to Hong Kong a day later which was also very warm and sunny.
In my experience: best time to go, driest time of the year, and sunniest, and least humid.