How to Stop Particle Lag in Rain and Weather Mods with Async Particles

Why rain tanks your FPS

Weather mods like Pretty Rain spawn huge numbers of short-lived particles every tick. Vanilla handles each particle on the main thread, so the game stalls while it ticks and buffers them all before rendering. Async Particles moves that work off the main thread and culls particles you cannot actually see, which is where most of the FPS recovery comes from.

Steps to reduce rain lag

1. Install Async Particles alongside your weather mod and launch the game once so its config file generates.

2. Open the mod's config (via the Mods menu config button, or the config file in your instance's config folder).

3. Enable particle culling. This skips particles outside your view frustum or hidden behind blocks, so rain falling behind you stops costing frames.

4. Leave asynchronous ticking and buffer filling enabled. These are the core features and are safe to keep on by default.

5. If you use shaders, test with them on and off. Some shader packs replace particle rendering entirely, which can reduce or negate the benefit.

6. Reload or restart, then stand in heavy rain and compare FPS with the mod disabled versus enabled.

Tuning tips

If you see particles popping in at the edges of your screen, loosen the culling distance rather than disabling culling outright. If you still lag, reduce your weather mod's own particle density first, then let Async Particles handle the rest.