Weather System - Storms, Rain & Snow

Weather System

Overview

A drop-in weather system for any Roblox game. 6 themed presets (Clear, Rain, Storm, Snow, Fog, Sandstorm) with smooth crossfading transitions between them. Camera-anchored particles always fall around the player wherever they walk. Ambient looping audio crossfades on weather change. Dynamic lightning during storms with delayed thunderclaps that simulate speed-of-sound distance. Weighted random auto-cycle with min/max durations. Auto-detection of CoreShun Day/Night Cycle for phase-aware storm probability and zero-conflict coexistence. Optional on-screen widget showing current weather. Full buyer hooks for wiring game logic to weather events.

Set StartingWeather and the system handles the rest. Drop-in, done.

Open source. Plain Luau. No obfuscation. Edit any file.

The 6 Presets

Each ships with

ParticleEmitter config — color, size, lifetime, speed, spread, acceleration, all configurable
Looping ambient sound — SoundId, volume, pitch (DEFAULTS EMPTY — buyer adds their own audio from Studio Toolbox; pcall'd Soundlay() silently no-ops on empty/invalid ids so zero errors out of box)
Lighting deltas — additive fog adjustments, brightness offsets, atmosphere shifts
ColorCorrection layer — brightness/contrast/saturation/tint applied to its own CC instance
Lightning toggle — only Storm has it on by default

Built-in weather types

Clear — no precipitation, no sound, neutral lighting
Rain — soft vertical rain streaks, mild blue tint, modest fog boost
Storm — heavy rain + LIGHTNING flashes + delayed thunderclaps, dark + oppressive, dense fog
Snow — slow drifting flakes, cool desaturated tint, modest white fog
Fog — native Roblox atmospheric haze (Atmosphere.Density + Haze 6.0), no particles, real obscured-distance visibility
Sandstorm — native warm-orange atmospheric haze (Atmosphere.Haze 5.5 + orange Color/Decay), no particles, real "blowing dust" feel

Smooth Transitions

Particle crossfade — old emitter ramps to zero while new one ramps up, simultaneously
Sound crossfade — TweenService volume tweens for both sounds, fade duration configurable
Lighting interpolation — fog, brightness, color correction all lerp linearly between presets
Configurable duration — 5s default for a cinematic feel; 0s for hard cut; 30s for very gradual
Per-call override — pass transitionSec to SetWeather to use a custom duration for one transition

Lightning

Only fires during weather presets with LightningEnabled = true (just Storm by default).

Random intervals — default 4-12 seconds between strikes; configurable (~5-10 strikes per minute during storms)
Screen flash via dedicated CoreShunWeather_LightningCC ColorCorrection (stacks with other CCs natively, no conflicts)
Delayed thunderclap — 0.4-4.0s random delay simulates speed-of-sound distance to the strike
Volume variance — quieter = more distant; configurable min/max
Pitch variance — slight pitch randomization per strike for realism
Suppressed during transition-in — won't strike during the first half of a Storm fade-in (avoids jarring "lightning the moment storm starts")
OnLightningStrike hook — fires per strike with intensity value; trigger screen shake, flicker world lights, scare NPCs

Weighted Auto-Cycle

Probability table — per-weather weight, normalized at pick time
Set weight to 0 to never auto-pick a weather (you can still manually SetWeather)
Random duration — min/max duration per hold, defaults 3-8 minutes
Anti-repeat option — never picks the same weather twice in a row
Pause / Resume — freeze the cycle for cutscenes, resume later
Force next cycle — skip to the next auto-pick immediately via _G.CoreShunWeather_ForceNextCycle()

Day/Night Cycle Integration

If you have CoreShun Day/Night Cycle installed (any version), Weather auto-detects it at boot:

Reads phase via _G.CoreShunDayNight_GetPhase() and applies per-phase probability multipliers
Default biasing — storms 2.5× more likely at Night, fog 1.5× more likely at Dusk, sandstorms 1.5× more likely at Day, etc. All configurable.
Defers Fog + Atmosphere to Day/Night by default — no race condition, no flicker
Still applies own ColorCorrection — stacks natively with Day/Night's CC for combined effect (stormy + dusk = cinematic)
Zero changes needed to Day/Night v1.0 — fully forward-compatible
ForceFogOverride flag — set Config.DayNight.ForceFogOverride = true to let Weather write to Lighting.Fog + Atmosphere ANYWAY during Fog / Sandstorm weather (true atmospheric haze even with Day/Night integrated). Default off for clean coexistence.
Opt-out flag — set Config.DayNight.IntegrateWithDayNight = false to manage Fog + Atmosphere directly without coexistence

Camera-Anchored 3D Volumetric Particles

Always around the player — 3D emitter column (80 studs tall) follows the camera every Heartbeat
Particles spawn in 3D space — above, at eye level, and around the camera — so weather is visible at every camera angle / zoom (not just hanging above the player)
Configurable height — particles spawn at and above the player; the emit column's ceiling sits HeightAboveCamera studs above the camera
Configurable spread — emit radius around the player
No zones to author — works in any game, any map, any geometry
Performance-tunable — Particles.GlobalRateMultiplier scales rate down for low-end mobile
Re-binds on camera change — works with custom camera systems

Optional Widget

3 display formats — "icon" (just dot), "name" (just text), "both" (icon + text)
Phase-tinted icon — colored dot matches the current weather's IconColor (yellow Clear, blue Rain, purple Storm, etc.)
Pure scale sizing — UDim2.fromScale + Min/Max pixel clamps, looks identical on every device
Mobile auto-position — relocates on phone-only devices to avoid Roblox jump button
Configurable everything — position, anchor, size, font, colors, border, corner radius
Disable in one line — Config.Widget.Show = false

Buyer Hooks

Define handlers in Config.Hooks (preferred) OR set on _G.CoreShunWeather_OnXxx at runtime. Hooks are pcall'd in task.spawn'd coroutines — a buggy hook can't crash the system.

OnWeatherChange(prevWeather, newWeather) — fires at the START of every transition. Spawn enemies, swap music, mute outdoor radios.
OnTransitionComplete(weather) — fires when fade settles. Useful for state-machine games that wait for "fully in weather X".
OnLightningStrike(intensity) — fires per Storm flash. Trigger screen shake, flicker world lights, scare NPCs.

Runtime API (_G Hooks)

Reading:

_G.CoreShunWeather_GetWeather() — current weather name
_G.CoreShunWeather_GetPreviousWeather() — previous, or nil if settled
_G.CoreShunWeather_GetIntensity() — 0..1 transition progress
_G.CoreShunWeather_GetTimeRemaining() — seconds until next auto-pick
_G.CoreShunWeather_IsCyclePaused() — boolean
_G.CoreShunWeather_IsTransitioning() — boolean

Controlling (server-side):

_G.CoreShunWeather_SetWeather(name, transitionSec?) — manual override
_G.CoreShunWeather_PauseCycle() — freeze the cycle
_G.CoreShunWeather_ResumeCycle() — unfreeze
_G.CoreShunWeather_ForceNextCycle() — skip to next pick now

Custom Presets

Adding your own weather takes ~15 lines.

Open WeatherPresets.lua and append a new entry with Particle, Sound, Lighting, ColorCorrection sub-tables. Then add a Probability weight in WeatherConfig.Cycle.Probability. That's it — the system picks it up at next boot.

Defensive Design

Pcall everything external — Lighting writes, Atmosphere mutations, Soundlay, hook invocations, time API
Bounded state — emitters and sounds clean up after transitions; no leaks
Lerped interpolation — all numeric and Color3 deltas blended smoothly between presets
Graceful boot — if Config or Presets fail to load, script no-ops with a clear warn (doesn't crash)
Graceful asset failures — invalid SoundIds, malformed particle configs all caught silently
Hook isolation — buyer hooks task.spawn'd and pcall'd; a buggy hook only logs a warn
No assumptions — every config field has a sensible default

Replication

Attributes-based — server writes 4 attributes on ReplicatedStorage.CoreShunWeather_State (Weather, WeatherFrom, Intensity, TransitionDuration)
Auto-replicates — Roblox replicates attribute changes to all clients automatically
Client reads directly — no RemoteEvent for state, no drift
One RemoteEvent — only used for per-strike lightning broadcasts (intensity + delay + pitch)
Server-authoritative — same weather for all players in a server

What's Included

CoreShunWeatherSystem.rbxmx — drop into Workspace + run installer
WeatherConfig.lua — single config ModuleScript (the only file you edit)
WeatherPresets.lua — 6 weather presets (extensible)
WeatherServer.lua — state machine, cycle, lightning, replication
WeatherClient.lua — particles, sound, lightning visuals, widget
Installer.lua — one-click command bar installer
Manual.pdf — comprehensive feature guide with examples
Cheatsheet.pdf — visual quick-reference
README.txt — setup + reference
Rojo project — for active development

Easy Installation

Drag CoreShunWeatherSystem.rbxmx into your place
Open the Studio Command Bar
Run require(workspace.CoreShunWeatherSystem.Installer)
Open WeatherConfig in ReplicatedStorage and customize (or skip — defaults work)
Press F5 — weather auto-cycles, storms trigger lightning, widget appears top-right

Frequently Asked

Can I have a permanent storm?
Yes. Config.Cycle.Enabled = false and Theme.StartingWeather = "Storm". Or _G.CoreShunWeather_PauseCycle() + _G.CoreShunWeather_SetWeather("Storm") at runtime.

Does this work with CoreShun Day/Night Cycle?
Yes — auto-detected at boot. Coexistence mode is enabled by default: Weather reads the phase for probability bias and defers Fog + Atmosphere to Day/Night. Zero conflicts. Day/Night v1.0 needs no updates.

Will Weather slow my game?
Server: minimal (20Hz tick + occasional weather pick). Client: ~5500 particles in flight at storm peak, distributed across a 3D volumetric emitter. Modern devices handle this easily. Pcall overhead is microseconds. Use GlobalRateMultiplier to scale particles down for low-end mobile.

Can I have per-region weather?
Not in v1 — Weather is server-wide. Per-region weather is on the roadmap. For now, you can manually SetWeather based on player position in your own scripts and skip the auto-cycle.

How do I disable a weather type entirely?
Set its Probability to 0 in Config. It can still be picked manually via SetWeather, just won't auto-cycle to it.

How do I add my own weather?
Open WeatherPresets.lua, append a new preset table, add a probability weight in Cycle.Probability. ~15 lines total.

Particles aren't showing — why?
Check (1) Particles.Enabled = true, (2) the WeatherClient LocalScript is in StarterPlayerScripts, (3) you're in play mode (not edit). If you're indoors, the building above blocks the camera-anchored emitter — that's intentional.

Lightning fires too often / too rarely.
Adjust Lightning.MinIntervalSeconds + MaxIntervalSeconds. Default 4-12s gives ~5-10 strikes per minute during storms.

Open source?
Fully. Plain Luau, no obfuscation. Edit any file.

Pairs Well With

CoreShun Day/Night Cycle — auto-detected at boot for phase-aware storm probability. Completes the "world ambience" trio with Music Player.
CoreShun Quest System — gate weather-themed quests via _G.CoreShunWeather_GetWeather() in CanAccept predicates.
CoreShun Toast — fire a notification on OnWeatherChange ("A storm is coming...") for player immersion.
CoreShun Music Player — swap to a stormier playlist on OnWeatherChange.

More Tools by coreshun

In-Game Systems — Day & Night Cycle, Quest System, Settings Menu, Music Player, Simple Music Player, Daily Rewards, Loading Screen, Advanced Chat System, Toast, Anti-Exploit, AutoRejoin, Codes Redemption, Crash & Error Reporter
Studio Plugins — Color Picker, UI Wireframe, Gamepass Manager, TODO Tracker (free)
Bundles — up to 45% off

Browse all: builtbybit.com/creators/coreshun

Support

Discord: discord.com/invite/hdB5tadkk8

$5.99 · 6 themed presets · Smooth transitions · Lightning + thunder · Day/Night integration · Buyer hooks · Open source

Weather System - Storms, Rain & Snow v1.0

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