The environment in Valheim changes constantly, through a day and night cycle, weather, biome and event effects.
Swamps use an environmental effect that causes them to be dark at all times. Additionally, it always rains in the Swamp, making combat in the biome more difficult.
Day and night cycle[]
Valheim days are 21 minutes long, with nights being 9 minutes long. A full loop is 30 minutes. Each 1 minute and 15 seconds in real time is equivalent to 1 hour in a Valheim day.
Day[]
The day starts when there is a popup announcing the new day (eg. Day 12). There is also a musical cue that can be heard, though the popup is much more noticeable. The 24-hour equivalent is 3:36.
The sky begins to lighten at that point, and daytime proper runs from 6am to 6pm. The sun and moon can be seen under a clear sky, and the direction of shadows will follow their position. The color of ambient lighting, and the density and color of fog, also change.
Some biomes are permanently darkened, see below.
Night[]
The night starts when the 'You feel cold' announcement pops up when standing outside (this will not appear if the player is wearing cold-resistant armor or is under the effect of a frost resistance mead). There is also a musical cue that can be heard. The 24-hour equivalent is 20:24.
Each biome's hostile mobs spawn more frequently at night. Additionally, certain mobs, such as Wraiths and Fenrings, or higher-star variants of some mobs, such as Wolfs or Gjalls, only spawn at night. They despawn once they unload during daytime.
There is a high chance that a thick fog will limit visibility in the plains towards dusk and especially dawn, though it is not limited to these time frames only.
Sleeping[]
Sleeping in a bed or dragon bed can be used to skip the night. The player always wakes up shortly before a new day starts.
When the day starts, the player will have to wait 10 minutes and 30 seconds before they are able to go to bed (until the afternoon). Sleeping causes time to progress, meaning e.g. smelters will process metal within until they run out of resources.
A decent way to keep time in Valheim is by sleeping with comfort 14. This will give you 21 minutes of the rested bonus, though spending time in a comfortable area will prevent the timer from going down.
Weather[]
Wind[]
The direction and force of the wind changes periodically. The direction is shown as an arrow in the lower-left corner of the minimap. The intensity is not shown in the interface, but can be heard, and stronger winds will produce gust lines and leaves blowing through the world. The strongest possible wind is 20 times stronger than the weakest.
Wind affects sailing and windmill processing speed.
If the wind is blowing against the player's intended direction of travel, it becomes impossible to move a boat forward with the sail unfurled, and it can only crawl forward at the lowest speed. Moder's power changes the wind direction while sailing (while steering the ship), but not wind intensity.
Rain[]
During rainy weather, players and objects not under a roof become wet. A roof will protect from rain if it is within 100 meters directly above the center of the object in question. This is not the same as the Shelter Effect—shelter checks that a player is mostly enclosed in all directions, whereas rain can only be deterred by a non-"leaky" object directly above. Currently, only thatched and shingle roof pieces qualify.
Built structures and objects exposed to rain (or still water) will be damaged for 1/20 of their health per minute, but cannot be reduced below half of their health by weathering. They may appear increasingly worn as their damage increases.
Fog[]
A fuling tower is roughly visible 30m away (right), and a tower 80m is almost completely shrouded by the fog (middle).
Fog can be experienced in the ocean, or in the plains. It severely limits visibility, with objects over 100m away being nearly impossible to see. Fog will significantly decrease the efficiency of windmills.
Temperature[]
Locations may be cold or freezing. Generally, all locations not near a fire become cold at night. Mountains are freezing regardless of the time of day.
Weather effects by biome[]
The probability of a given weather occuring in a given biome is listed below. Note that Mistlands do not have "foggy" weather, as their permanent mist is created using other effects.
| Weather | Probability |
|---|---|
| Clear | 86% |
| Fog | 3% |
| Light rain | 3% |
| Rain | 3% |
| Thunderstorm | 3% |
| Weather | Probability |
|---|---|
| Clear | 87% |
| Fog | 4% |
| Rain | 4% |
| Thunderstorm | 4% |
| Weather | Probability |
|---|---|
| Rain | 100% |
| Weather | Probability |
|---|---|
| Snowing | 83% |
| Blizzard | 83% |
| Weather | Probability |
|---|---|
| Clear | 71% |
| Fog | 14% |
| Rain | 14% |
| Weather | Probability |
|---|---|
| Clear | 88% |
| Rain | 6% |
| Thunderstorm | 6% |
| Weather | Probability |
|---|---|
| Clear | 71% |
| Fog | 7% |
| Light rain | 7% |
| Rain | 7% |
| Thunderstorm | 7% |
Environment effects[]
Biome effects tie the weather and other environment effects to each biome. Additionally, some dungeons or raids utilize some of these effects.
Each weather effect can be set by using the 'env' (enviroment) debug console command if, followed by a space and then their tag. (The tag will be listed with each weather condition in parentheses). Cheats must be enabled to do this.
- Clear skies (env Clear)
- Light Rain (env LightRain)
- rain (env Rain)
- Thunderstorm (env ThunderStorm)
These weather effects will influence the size and frequency of waves within the Ocean biome.
Some biomes force a weather effect upon entry, and are persistent as long as you are in that biome:
Other biomes have specific weather with intermittent changes:
- Mountain Snow (env Snow)
- Mountain Blizzard (env SnowStorm)
- Black Forest Fog (DeepForest Mist)
- Plains Fog (env Misty)
- Ocean Fog (env Misty)
Each boss also forces their own unique weather effect:
- Eikthyr's Thunderstorm (env Eikthyr)
- Elder's Haze (env GDKing)
- Bonemass's Downpour (env Bonemass)
- Moder's Vortex (env Moder)
- Yagluth's Magic Blizzard (env GoblinKing)
As mentioned earlier, there are some extra weather effects that are used to control the ambience of dungeons (env Crypt, env SunkenCrypt).
There is a very special weather effect that appears to be a thunderstorm, but what sets it apart is the being that can be seen crossing the sky, arcing bolts of lightning from a carriage drawn by two beasts. This being is assumed to be Thor, though upon close inspection, the model and textures are incomplete (env nofogts).
Travelling between biomes using a portal causes the environment effects to blend, e.g. causing it to snow in Meadows after teleporting from Mistlands.