WeatherOverhaul

Valheim's weather is a painted backdrop: flat cloud layers, a sky that is mostly a colour gradient, and a thick fog that hides everything a few hundred metres out. WeatherOverhaul replaces it with a real sky. Clouds have volume and drift with the wind, rain comes in under a dark front, the air is clear enough to see the next island, and sunlight falls through the trees in shafts. Everything still follows the game's own weather, biomes and time of day, so a storm is still a storm and the Mistlands still look like the Mistlands.

What you get

• Sky. A physical atmosphere: blue days, red and golden sunsets, a long twilight after the sun goes down and a moonlit night. The game's stars, northern lights and sun stay. The moon goes through its phases over 30 game days.
• Clouds. Volumetric clouds instead of the flat layers: fair-weather cumulus, broken clouds with the sun in the gaps, dark rain and storm decks, snow and fog banks, and cirrus high up that catches the sunset. Their shadows sweep over the land on fair days, and water reflects them.
• Weather fronts. A change of weather shows up upwind first and passes overhead when the game switches. Distant rain falls from the clouds in grey shafts.
• Lightning. Bolts, flashes inside the clouds and thunder that arrives late from far strikes. Thunderstorms can also come to the Plains and the Swamp, where the game has none.
• Clearer air. You see 5 to 8 times further than in the vanilla fog: about 6 km on a clear day, about 1 km in rain. Fog thins out with height, so hilltops rise out of it. Some mornings have mist in the lowlands, and a light mist lies over the open sea. The Mistlands keep the game's own short view.
• Light shafts. Sun and moonlight fall through gaps in trees, mountains and clouds, strongest in mist and haze.
• Snow. Softer falling snow that roofs and rock keep off, snow drifting along the ground in strong wind, and a snow layer on the mountains that covers the rocks too.
• Puddles. Rain fills small dips in the ground. You can see the bottom through the water, raindrops ring the surface, and the puddles dry up after the rain.
• Fireflies. On dry nights in the Meadows, the Black Forest and the Plains.
• Biomes keep their mood. Ash and a red glow over the Ashlands, low lilac clouds over the Mistlands, cold clean air in the Deep North, humid haze over the Swamp.

Requirements

• BepInEx for Valheim (required)
• Configuration Manager (optional; every setting can be changed while you play)
• FarLands (optional; with it the air also lies over FarLands' distant land)

Installation

1. Close Valheim.
2. Extract the archive into the Valheim game folder, so that the DLL ends up at Valheim/BepInEx/plugins/WeatherOverhaul.dll. With a mod manager, install it as usual.

Multiplayer

Client-side only. The server and other players need nothing, and nothing is written to your world. Players who have the mod see the same sky, clouds and air, because all of it comes from the world's own weather and time. Players in one thunderstorm see the same lightning strike at the same moment and hear the same thunder. The rare bolts close to a player are shared only with players who have that player loaded (about 100 m) or who see them on the map. The clouds' drift and fireflies are worked out on each machine, so they differ between players.

Performance

At Ultra with every part on, the mod costs about 2.4-3 ms of GPU time per frame at 2560x1440 on an RTX 4070 SUPER, mostly for the clouds. On a weaker card pick a lower Profile, or turn off the parts you can live without.

Settings

Everything is in BepInEx/config/ru.ivest.weatheroverhaul.cfg and changes apply while you play. Each part of the mod has its own section with an Enabled switch. Turning a part off gives you the game's own version of it back.

General

Setting	Default	What it does
Profile	Auto	Quality: Auto picks one for your PC; Low, Medium, High and Ultra force one; Custom is Auto plus your own changes.

Settings set to -1 follow the profile. Any other value overrides the profile for that setting only.

Sky

Setting	Default	What it does
Enabled	true	The physical sky.
SkyBrightness	0.8	Daytime sky brightness compared to the game's.
NightBrightness	1	Night sky brightness compared to the game's.
MoonPhases	true	Moon phases over 30 game days, the same for every player. Off: a full moon every night.
MoonPhaseKeys	true	The moon's phase as a world key for other mods' scripts (e.g. only at the full moon): moon_new, moon_waxing_crescent, moon_first_quarter, moon_waxing_gibbous, moon_full, moon_waning_gibbous, moon_last_quarter, moon_waning_crescent. Changes at noon, so a night has one phase. Set by any player with the mod; the server needs nothing.
MoonPhaseKeyPrefix	moon_	The moon keys' prefix.
MainMenu	true	The sky and clouds over the main menu too.
MainMenuSun	2.5	The sun's height over the main menu, in degrees (11 = the game's own menu evening, below 0 = dusk).
VanillaSkyColour	1	How much of the game's own sky colour to keep (0 = pure physical colours).
HorizonFog	true	Fades distant land into the sky's colour. Only used while Air is off.
Clouds	true	Volumetric clouds.
CloudBrightness	0.7	Cloud brightness. Lower gives grey bases and more shape.
ExtraCloudLayers	true	Altocumulus and distant towering cumulus on some fair days.
CloudParallax	0.5	How much the clouds shift as you move. 1 = like real clouds, 0 = fixed like the game's.
CloudShadows	true	Cloud shadows on the land.
StormFlashes	true	Lightning flashes inside storm clouds.
FrontLeadSeconds	90	How early a new weather's front appears. 0 turns fronts off.
YggdrasilFog	0.5	How much of its own haze the world tree keeps (1 = as in the game).
YggdrasilAirHaze	true	The air's haze over the world tree, like over distant land.
YggdrasilBehindClouds	true	Draw the world tree behind the clouds rather than in front of them.
CloudVariant	0	For browsing: shows the current weather with the sky of a later weather period. Set back to 0 to play.
HighLayer	the period's own	For browsing: shows one of the high cloud layers. Set back to the period's own to play.
SkyViewSteps, CloudSteps, CloudResolution, DomeResolution, ShadowResolution	-1	Quality of the sky, clouds, cloud reflections and cloud shadows.

Air

Setting	Default	What it does
Enabled	true	Clearer air instead of the game's fog.
AirStyle	North	North: clean northern air, deeper blue at dusk. Earth: an average atmosphere.
Haze	Standard	Clear, Light, Standard or Thick. Sets the three haze settings below at once; changing one of them by hand shows Custom.
NearHaze	0.6	How much of the game's haze stays close to you.
NearHazeDistance	50	Over how many metres the near haze fades out.
FarLandsHaze	1	Haze over FarLands' distant land in clear weather (only with FarLands).
VisibilityScale	1	Multiplies how far you can see in every weather.
MistLimit	0.8	How much the morning mist can hide in the distance. Higher turns it into a grey wall; 0 = no limit.
SeaMist	true	Mist over the open sea, so distant shores fade instead of all being in view.
SeaMistOnlyAtSea	true	Only show the sea mist while you are out at sea.
SeaMistVisibility	1500	How far you see through the sea mist, in metres.
SeaMistHeight	150	How high the sea mist reaches, in metres.
HazeInReflections	true	Water reflects distant shores through the haze.
VolumetricLight	true	Light shafts in the air. Off on Low.
ShaftStrength	1	How dark the shadowed air is; higher makes the shafts stand out. 0 turns them off.
FogDistance, FogSlices	-1	Reach and detail of the light shafts.

Lighting

Setting	Default	What it does
NightAmbientBoost	0.25	Brightens the ground and objects at night (0 = the game's darkness). Leaves days and dungeons alone.

Lightning

Setting	Default	What it does
Enabled	true	This mod's lightning and thunder in thunderstorms.
PlainsStorms	0.3	Share of rainy weather in the Plains that becomes a thunderstorm. Players without the mod just see rain.
SwampStorms	0.1	The same for the Swamp.

Precipitation, SnowCover

Setting	Default	What it does
Precipitation.Enabled	true	This mod's falling snow.
Precipitation.GroundDrift	true	Snow blowing along the ground in strong wind.
SnowCover.Enabled	true	The snow layer on the mountains, within 160 m of you.
SnowCover.RockCaps	true	Snow caps on mountain rocks. Off on Low.

Puddles

Setting	Default	What it does
Enabled	true	Puddles.
MinArea, MaxArea	1, 60	Size range of the dips that fill up, m².
MinDepth	0.02	Shallowest dip that fills up, metres.
MaxDepth	0.3	Deepest a full puddle gets, metres; a deeper hole keeps a puddle at its bottom.
FillSeconds, DrySeconds	180, 600	How long it takes to fill in rain and to dry afterwards.
WaterTint, Turbidity	brownish, 0.3	Colour and murkiness of deeper water.
WetDarkening	0.3	How much darker the wet bottom is.
RippleStrength	0.6	Raindrop rings.
ExcludedBiomes	Mountain,DeepNorth,AshLands	Biomes without puddles.
ReflectionSteps	-1	Reflection quality. 0 uses only the game's reflection.

Fireflies

Setting	Default	What it does
Enabled	true	Fireflies.
Count	15	Most firefly swarms around you at once.

Sky types, Weathers

Adjust a single kind of weather; these sections come after all the others. Sky types covers each kind of sky the clouds draw: Fair and Broken (the clear weathers), Fog, Rain, Storm, Snow, Blizzard, Polar clear, Ash, Ash storm. Weathers covers each of the game's weathers by name, including other mods' weathers. It appears after you first enter a world. A weather's own values add to those of its sky type (the cover adds, the rest multiply). The log names the sky type of each new weather (sky type ...).

Setting	Default	What it does
Broken days	0.5	Share of clear-weather days with broken clouds instead of fair ones (0 none, 1 all).
... - Cloud cover	0	More clouds (up to 1: a closed sky) or fewer (down to -1: none).
... - Cloud brightness	1	Multiplies the clouds' brightness.
... - Sky brightness	1	Multiplies the sky's brightness by day and night. The land's light follows it only under clear sky, not under a closed sky (rain).
... - Visibility	1	Multiplies how far you can see.
... - Light	1	Multiplies the light on the land, by day and night. The sky keeps its brightness.
... - Light tint	white	Colour of the light on the land. The clouds and fog take on some of it.

Compatibility

Checked against the code of these mods, not yet in play with each of them.

• FarLands: made to work together. With the Air on, WeatherOverhaul draws the air over FarLands' land.
• Valheim Visual Enhanced: both mods add cloud shadows and fireflies. Turn off one set, here with Sky.CloudShadows and Fireflies.Enabled.
• Seasonality: its winter snow gets this mod's snowfall.
• VBDiving, Dive In: under water the mod's own underwater fog stays as it is.
• Expand World Size with Stretch world changed: the Ashlands' sky starts where an unstretched world's would.
• Mods that replace the skybox turn the physical sky off while they are active.

Platforms

Windows with Direct3D 11, Direct3D 12 or Vulkan; Linux through Proton. A native Linux build of the shaders is included but has not been tested.

For mod authors

Public hooks, all in the WeatherOverhaul namespace. A handler or provider that throws is logged once and skipped.

• Weather.Current: the weather this mod uses this frame (rain, snow, wetness, fog, wind), default outside a world.
• StormFlashes.Flashed: an event for every lightning flash, with its position, size, strength and length.
• Ownership.Current, Ownership.Owns, Ownership.Changed: what this mod currently draws in place of the game (sky, clouds, fog, snow and so on), so your mod can leave it alone.
• PrecipitationSurface.Height: tell the snow drift where the visible ground is if your mod draws it above the collider.
• NightLighting.Ambient: the night ambient this mod sets, for mods that compute the game's lighting themselves (portal views and the like).
• BuiltInFog.Density: the fog density that matches this mod's air, for mods that draw a place with Unity's built-in fog.

Credits

• Sky: Sébastien Hillaire's atmosphere (EGSR 2020).
• Volumetric clouds and light: ported from Unity HDRP.
• Skies and snow textures: Poly Haven (CC0). Thunder: freesound.org recordings (CC0).

Full licences are in THIRD_PARTY_NOTICES.md.

Problems and feedback

Write to me on Discord: https://discord.com/users/683075123816824940, or post in the Bugs tab. Attach BepInEx/LogOutput.log from the game folder, or from the profile folder with a mod manager (r2modman: Settings → Browse profile folder), and say what you did when it happened. A screenshot helps with anything visual.

Uninstallation

Close Valheim and remove Valheim/BepInEx/plugins/WeatherOverhaul.dll. The settings file BepInEx/config/ru.ivest.weatheroverhaul.cfg can be kept or deleted; nothing is stored in your worlds.