While the weather might be humid and rainy, it's still a great time to train in Thailand! Specifically in northern Thailand, where the rain makes it cooler than the Bangkok area. 

There are significantly fewer tourists around (due to the rainy season), which means not only are tourist attractions cheaper and easier to navigate, but you will get more individualized training in the gym! 

If there are fewer people in the gym, there is more time for the teachers to focus on you!! Often, for group classes, there are only 1-2 other people in the gym (if anyone at all), making the classes feel more like a small private group than a normal group class. Private feeling training for group class prices! 

You will also get a more authentic experience. With fewer tourists around, you will likely see more local Thai residents in the gym. It's a different experience than training during high tourist season. 

Highly recommended!