When you travel, you are going to want to know what the weather will be like, so that you can pack the right clothing. Since you want to take as little as possible, it will be helpful to know whether you need a full coat or if a sweater will do for cool nights.
Likewise, if you don’t care for a particular type of weather, then knowing in advance will help you plan your trip.
Of course, some activities will be cancelled due to inclement weather, so another reason to know in advance is to understand when the same patterns occur. For example, hurricane or monsoon seasons.
But all in all, most travelers take the weather in stride once they get to their destinations. It is what it is!