By April throughout Laos things are starting to heat up with a marked increase in humidity as the monsoon nears.
This is still a very good time for touring Laos, although an extra bottle of water and a cold towel might be in order for wandering around the temples in Luang Prabang or climbing the steps to Mount Phousi.
Temperatures are a few degrees higher at this time of year, averaging around 30 degrees in central and northern Laos and 5 or 6 degrees higher in the south.
The extra degrees and increased humidity can take its toll with busy days clambering over ruins, so bear this in mind.
Rainfall throughout Laos is still low at this time of year unless the monsoon rains arrive particularly early, at the end of the month.