One issue is that it can be leveraged to maintain a monopoly. Microsoft famously made a bunch of small modifications to the HTML standard, so that web sites that wanted to work with MS Internet Explorer had to write custom versions to be compatible. But because so many people just used IE because it was bundled with Windows, those "extensions" started to become their own standard, so that then other browsers had to adopt MS's idiosyncrasies in order to be compatible with the sites, which in turn harmed standardization itself. They even had a term for this technique: "Embrace, Extend, Extinguish." It nearly worked for them until Google pushed them out with Chrome. Microsoft tried to do the same thing again with Java until the government got involved.
It's complicated, certainly, but there are legitimate cases where "just a little tweak" can be quite a big problem for a standard.
Sound doesn't travel as far through warm humid air, so the world feels a little more muted and calm. (Contrast this with the dry, dense air of a frigid winter day, when the sound of cars carries for miles as a dull growl.) The light is almost entirely diffuse thanks to clouds, rather than the sharp glare of a sunny day; your skin isn't dried out and burned in the same way either. Public spaces aren't as crowded. Indoor rooms are often lighted more gently as well without sharp sunbeams drawing lines. Add the sound of rain itself and the faint smell of petrichor, and the improvement in the air quality as the rain washes particulate and pollen into the gutters, and you get a perfect day to curl up with a book, a cup of tea, and a cat on your lap.