If you really want to narrow down the best time to visit Thailand, November to February is much cooler and has the least amount of rain. Unlike many parts of the world, Thailand has only three seasons - summer, wet and winter. Summer is a popular time to visit with many travellers wanting to soak up the sun and enjoy the beautiful beaches however the temperature can get quite hot during summer, so visitors should be prepared. It's also important to remember that Thailand is a large country and different regions have different landscapes and therefore experience different conditions. For example, southern Thailand doesn't really experience a winter.