For good weather and festivals, late September
Papua New Guinea(Goroka), Goroka Show (gathering of the clans), the weekend around Sep 16 (Independence day), 3 days. .
Thailand, Anantara Resort (Gulf coast), King’s Cup Elephant Polo Tournament, 17-22 Sept.
Swaziland (Lobamba), Umhalanga (traditional ceremony with Reed dance), late Aug- early Sep, 1 week.
Bolivia (Oruro), Feast of the Cross (costumed dances)14th.
(Tarija), Festival of San Roque (folk music, dances and parades), starts the first Sunday, 8 days.
Or go for festivals only, not the weather! i.e. this is not the best season
Morocco (Imilchil) Engagement Festival (Tribal gathering) third week in Sep, 3 days. Morocco Pictures.
India Alappuzha & Kerala), Onam Harvest Festival (Nehru Cup Snakeboat Race) Aug/Sep, 10 days
(Nationwide), Dussehra -Ram Lila (Hindu celebration) Sep/ Oct, 10 days.
(Kulu), Festival of the Gods, Sep/Oct, 10 days. India Pictures.
Nepal (Kathmandu, Patan), Bada Dasain (Hindu festival) Sep/Oct, 10 days.
Vietnam (Nationwide), Trung Nguyen (feast for wandering souls and hungry ghosts), full moon day in Aug/Sep.
Taiwan (Nationwide), Hungry Ghost Festival, Aug/Sep, 1 month. Vietnam Pictures.
Myanmar (Inle Lake), Phaungdaw Festival (Floating villages’s water processions and boat races), Sep/Oct, 1 day.
Bhutan (Tashichho Dzong, Thimphu), Thimphu Tsechu (spiritual festival with masked dances), Sep/Oct, 3 days.