South Asia
Sri Lanka travel dress guide
Sri Lanka is a small island with two monsoons, and that is the first thing that decides what to pack. The southwest monsoon brings rain to the west and south coasts and the hill country from roughly May to September; the northeast monsoon reaches the north and east from about October to February. So there is almost always a dry coast somewhere, and the right clothes depend on which side of the island you are on as much as on the month.
The lowlands are hot and humid all year, typically in the high twenties to low thirties Celsius, which calls for loose cotton and linen rather than anything synthetic. The hill country around Nuwara Eliya and Ella is a different climate entirely: mild days and cold nights, where a fleece earns its place in the bag.
Temples are the other half of the question. Buddhist sites expect covered shoulders and knees, and you remove your shoes and hat before entering — light trousers or a long skirt and a scarf solve most of it. These guides cover each month's weather, temple etiquette, and Sri Lanka's own traditional dress, from the Kandyan osariya to the sarong.