Weather effects can sell an area really well. (They can also be distracting if done wrong! That's also true.)
Here's fog and rain effects in Crucible Crest. (1:36:53 and 2:31:57 timestamps for fog and heavy rain, respectively. There's also lighter rain in a couple places.) In both cases I think the areas wouldn't have the same character without them.
In your example, I think there's more things you can do to sell the rain effect better. It's very brightly colored right now in contrast to the dark nighttime screen--originally I wasn't sure if it was supposed to be rain or snow. I would maybe up the translucency a bit so it doesn't stand out as much. I'd also definitely have animations for rain hitting ground, and not just have it going from the top of the screen to the bottom without ever landing. It might also be worth playing around with different angles for the rain, but I'm not sure you need that in every case--that'd depend on the strength of the rain.