March is a very good time to tour Laos, although things are starting to heat up throughout the country as the humidity starts to build a little bit with the approach of the monsoon.
Temperatures start to creep up a notch also towards the thirties. Temperatures average around 30 degrees in Vientiane and Luang Prabang and a couple of degrees higher further south.
Throughout Laos in March, expect clear and sunny skies, perhaps with the occasional short sharp shower.
March is still high season in the country and an optimal time for touring Laos.