Made with Blender 3.6. Rendered with Cycles at 64 samples and Denoiser. Rain is a simple particle system. Dynamic paint was used to make the paintmap, wetmap and ripples. A second particle system was added to create splashes where the paintmap dictates the rain landed.
I modelled the lamp-post for this project, but I used a scan of an alleyway and a model of a homeless person.
Credit for those goes to :
https://sketchfab.com/edemaistre -- Alleyway scan
https://sketchfab.com/alban -- Homeless model
It can't rain all the time