Weather will likely play an important role when you plan your trip to Samut Songkhram, but bear in mind that cheaper options are usually available when the weather isn't as good. The hottest months are usually April and May, with an average temperature of 30°C, while the coldest months are December and January, with an average of 27°C. The rainiest months in Samut Songkhram are September, October, May and July, with each month seeing an average of 201 mm of rainfall.