When I was there it was rainy in the mountains and fairly cool along the coast, about end of December first of January... Laos was cool in the norther mountains and around Luang Prabang but hot in the south and Vientien was very comfortable in the eveings and warm to hot in the afternoon sun. I would recommend at least 2 pair of shorts and 2 pair of long exoffico/northface style travel pants, they are light weight and you can wash and rinse in the sinks or just take a shower with them on and let them dry overnight. One light weight sweater, and an assortment of t-shirts is all I need. I always carried a rain poncho/light weight rain coat and supplement this with local clothes as needed. They are very cheap. Just remember to pack once and then dump everything on the bed and re-pack with only half the gear, and if you are really pressed do it one more time!
George almost 10 years ago