A lot of people do not think that they should travel somewhere that is experiencing a lot of rain because they will not get to enjoy the things that they are supposed to do. There are some places wherein you can go to experience the rain. Going somewhere during the rainy season will allow you to get discounts because the number of tourists is lower. This means that you can enjoy more time somewhere else.
In Vietnam, it is better that you go during the rainy season because it will allow the place to cool down enough for you to enjoy the rest of your vacation. Remember that rainy season does not mean that it is going to rain non-stop. It just means that it will rain for an hour or so in the afternoon while the rest of the day will be lovely enough.