Weather is probably a major factor when you plan your trip to Lai Chau, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually May and June, with an average temperature of 21°C, while the coldest months are January and December, with an average of 14°C. The rainiest months in Lai Chau are August, July, June and September, with each month seeing an average of 338 mm of rainfall.