Rainfall
by Palpex
Rainfall replaces the visual-only rain of 1.21.1 with a water simulation: precipitation collects on surfaces, forming puddles and streams.
What it does
Instead of rain that only falls on screen, Rainfall lets water accumulate on terrain. Puddles grow over time in low areas, spread according to the shape of the ground, and develop into streams that follow natural slopes. Where streams meet they merge into small runoff paths, linking separate water bodies without altering or destroying any blocks.
The simulation covers water flow, surface spread, evaporation and drainage, and is built to stay light enough for normal play. A built-in debug renderer is included: pressing P toggles a view of internal data such as flow directions and basin water distribution, and the config menu opens with K. The mod is listed as a work in progress.
Rainfall is a NeoForge mod for Minecraft 1.21.1 and nothing else. Only the player's game needs it, and servers run without it. It is released under the Creative Commons Attribution No Derivatives 4.0 license, and the project is not open source.
Key features
Accumulating puddles
Rain collects in low areas of the terrain and forms puddles that grow gradually during rainfall.
Flowing streams
Water spreads across slopes and develops into streams that follow the shape of the land.
Runoff connections
Streams merge into runoff paths that visually link separate water bodies.
Debug view
Pressing P shows internal simulation data such as flow directions and basin water distribution.
Gallery
Compatibility
Latest build for each game version and loader.
Only full game releases are shown. This mod publishes no snapshot builds.
Use cases
Rainy survival builds
Players who build in wet biomes can watch water pool around structures and route it through the landscape.
Who it’s for: Players who want weather with more visible effects on terrain, and anyone studying how water flow is simulated, through the built-in debug view.
How it compares
Puddles & Floods covers Fabric, Forge and NeoForge across 1.20 – 26.3 under the MIT License, and is open source; it only needs the client. Water Erosion Continued is a client and server mod for 1.21.1 under the GNU General Public License v3.0 only, and is open source. Rainfall stays NeoForge-only and client-side, with no server part.
| Mod | Loaders | Game versions | Environment | Updated |
|---|---|---|---|---|
| Rainfall | NeoForge | 1.21.1 | Client-side only | 2026-10-10 |
| Puddles & Floods | Fabric, Forge and NeoForge | 1.20 – 26.3 | Client required, server optional | 2026-09-29 |
| Water Erosion Continued | Fabric, Forge and NeoForge | 1.21.1 | Client and server | 2026-08-18 |
Questions
Does Rainfall run on Fabric or Forge?
Does a server need Rainfall?
Is the Rainfall source code available?
In the catalog
Rainfall is one of 12,078 Decoration mods on ModsFinder, and one of 5,201 Decoration mods for NeoForge. 32,366 mods support Minecraft 1.21.1.
More from Palpex
Similar mods
What the author says
Rainfall is a dynamic weather simulation mod that transforms Minecraft’s rain into a fully interactive water system. Instead of simple visual rain, precipitation accumulates on surfaces, forming realistic puddles that grow over time. Water spreads based on terrain shape, collects in low areas, and gradually develops…
Official listing
- Modrinth page
- modrinth.com/mod/rainfall
- Owner
- Palpex
- Published
- 2026-05-02
- Updated on Modrinth
- 2026-10-10
- Facts verified
- 2026-10-15