The Fog is a natural world entity found at the edges of the map in the Shipwrecked DLC. Entering the Fog will teleport the player to the opposite side of the map, and will cause the player to lose 15 .
When the player approaches the Fog, the character will make a comment to indicate the proximity. Once the character enters the fog control of the character will be lost, and the screen will fade out. Immediately after the screen will fade in to show the teleported character moving out of the fog. The control of the character will be regained when they completely exit the Fog.
A less dense version of the fog can also be found randomly on the Ocean during the first 2 segments of the day, and near Wrecks. These are just visual effects and have no functionality.
The Hamlet DLC introduces the Fog as a prominent mechanic in Humid Season, acting as a short event lasting from 1-3 minutes [Verification Needed] that occurs outdoors. It is indicated by a thick fog that covers the whole screen, reducing the visible area to a small radius around the player.
Players experience fatigue, in which they are weighed down by any wearable items equipped in the Head or Body slot, causing a significant reduction in movement speed. This is indicated by the character stating "This [item] is slowing me down" and seeming hunched forward as they move. Removing any items in the head/body slots will allow the player to move normally. Three exceptions exist to this, which both exist to negate the fatigue caused by fog: The Pith Hat or Cowl worn on the head, allowing the use of the body slot; and the Weevole Mantle worn on the body, allowing the use of the head slot. Using these two items in conjunction during Fog has no added bonus.
Once the Fog clears, heavy rain will occur for another 1-3 minutes,[Verification Needed] causing increased wetness unless the player is drying off inside the aforementioned shelters. After this, weather will return to being clear, and players may resume their activities with ease or dry off to reduce their wetness.
In the Shipwrecked DLC, due to the loss of control when entering Fog, Waves cannot be avoided, so caution is advised.
In the Hamlet DLC, outdoor exploration is dangerous during Fog due to the limited view. If a player wishes to explore, they are advised to carry the most basic minimums they require to explore, and to not equip any equipment to increase the player's mobility. However this can be averted if the player uses a Pith Hat or Weevole Mantle.
Webber players should be cautious when removing their Shamlet Mask (to reduce fatigue) near Royal Guards or neutral enemies such as Pogs, as they can start to attack the player once it is taken off.
Players are advised to utilize an Umbrella or waterproof clothing (such as the Snakeskin Hat or Snakeskin Jacket) to reduce wetness from Waves/post-fog Rain in the Shipwrecked or Hamlet DLCs respectively.
If one becomes very wet, quickly find land/shelter and place down a fire source to reduce the Wetness sanity drain (or additional damage, in the case of WX-78).