For good weather and festivals, early December
Philippines (Baguio, North Luzon), Grand Canao (dancing and rituals), Nov/Dec, 1 day?
(San Fernando, Pampanga province), Giant Lantern Festival, after midnight mass on 24th, 1 day
Argentina (Luján, Catamarca), Feast of the Immaculate Conception (colorful costumed procession), 8th, 1 day. Argentina Pictures.
For good weather and festivals, late December
Thailand (Lop Buri), banquet for monkeys, late-November/early December, 10am, Noon & 2pm, 1 day. It’s usually on Sunday of the last week of November at San Phra Kan and Phra Prang Sam Yot. Tourists who come to Chaopho Phra Kan bring food and fruit for the monkeys, but there’s plenty provided as well.
(Nakhon Phanom) Wan Phra Jao Prot Lok (Fire boats on Mekong River) Nov/Dec, 1 day.
Chile (Andacollo), Fiesta de la Virgin del Rosario (dancing, horse racing +) 24-28. Chile Pictures.
Guatemala (Antigua) wild Christmas eve celebrations
(Chichicastenango), Fiesta de Santo Tomás (Parades, dances and games), 13-21.
Mexico (Mexico City) Nuestra Senora Pilgrimage, 12th
(Oaxaca), Noche de Rábanos (Night of the Radishes) 23rd.
Or go for festivals only, not the weather! i.e. this is not the best season
Turkey ( Konya), Festival of Whirling Dervishes (spinning dance) mid-Dec, 1 day?
Tunisia (Douz), Festival of the Sahara (Harvest celebration), mid-Dec, 10 days.
Pakistan (Hindu Kush region), Chaumos (Winter Solstice Festival with music, dance animal sacrifices), mid-Dec, 12 days
Nepal (Thyangboche), Mani Rimdu (Buddhist masked dances) full moon in Nov/Dec, 1 day.