Kanchanaburi has a hot tropical climate with three distinct seasons; the humid and intense hot season, the west monsoon season and the cooler winter months. Visitors must consider the time of year when visiting Kanchanaburi because arriving in the wrong season can be either incredibly draining or a complete washout. The ideal months for visiting Kanchanaburi are between November through to March. These months are the ideal time for visiting the majority of Thailand. November is when the monsoon rains finish and March is when the humidity starts to increase making sightseeing difficult.
From March until June (when the monsoon rains start) temperatures and humidity can become unbearable. It is not uncommon in April for temperatures to be in excess of 40C and humidity close to 100%, so is regarded as the worst month to visit Kanchanaburi. During these months air conditioning becomes essential for sleep and even the slightest activity requires litres of water.
The wet season lasts from July through to the end of October, but the rains lessen towards the end of the season. During the wet season it is unlikely to have whole days of rain, usually rains are intense lasting less than a couple of hours followed by hot sun. It is possible to explore the area during September and October and as considered off-season massive reductions can be found. The height of the tourist season begins in November and lasts until mid February.
This is when accommodation becomes less available and popular tourist attractions, such as the Tiger Temple, are busy. Locals consider this season to be the cool season but visitors will still be walking around in shorts and T-shirts and switch on air-conditioning during the night. Daytime maximum temperatures reach 26C with humidity around 70% which is considered hot by most tourists.
The best time of year to visit Kanchanaburi is between mid-November to the end of January. The worst time of year to plan a holiday to Kanchanaburi is at the height of the hot season in April.