Weather

xTATTEREDx · +FINE+ · *SUPERIOR* · ≡EXCEPTIONAL≡ · ☼MASTERWORK☼

v50.15 · v0.47.05

This article is about the current version of DF.
Note that some content may still need to be updated.

Weather refers to any type of weather effect in DF. It includes snow, rain, and special features in evil surroundings.

Weather can be disabled by changing [WEATHER:YES] to [WEATHER:NO] in d_init.txt. Disabling weather is a quick and largely harmless fix to improve framerate on older machines if required.

Normal Weather

Clouds

Dwarf Fortress has three layers of clouds: cumulus, cirrus, and stratus. When using the W key in adventure mode, any number of messages about the weather may appear, and corresponding symbols are shown when c is enabled on the fast travel mode. The types of clouds that are possible are:

Clear sky (no clouds) — The sky is clear above you.

α Scattered cumulus — There are scattered puffy clouds above you.
β Many cumulus (causes rain) — There are mounds of clouds above you, smooth on the bottom with prominent upward bulges.
¶ Cumulonimbus (causes rain) — A dark, menacing cloud towers above you, crowned by an anvil.

≡ Cirrus — The sky is striped with thin clouds.

Altostratus — The sky above you is hazy and white.
█ Stratus (causes rain) — The sky above you is gray.
█ Nimbostratus (causes rain) — The sky above you is a uniform and dark gray.

Additionally, some unique messages occur when there are clouds in multiple layers:

Scattered cumulus and cirrus — There are scattered clouds underneath a striped sky.
Many cumulus and cirrus — Mounds of clouds are clustered through a striped sky.
Cumulonimbus and cirrus — A dark, towering cloud rises into a striped sky.
Altostratus and cumulonimbus — A towering gray cloud descends from the white sky above you.
Stratus cumulonimbus — The sky above you is completely gray, with dark cloud pillars pressing through it.
Nimbostratus and cumulonimbus — The sky above you is nearly black, ripped through with towering clouds.

Otherwise, stratus clouds prevent you from seeing if there are any cirrus or cumulus clouds.

Fog / Mist

Fog is another aspect of the weather, and is described separately from the state of clouds when using W. (However, thick fog prevents you from being able to tell what the clouds are like via W.) There are three kinds of fog that may appear:

░ Thin Mist — There is a thin mist here.
▒ Fog — Fog enshrouds the area.
▓ Thick Fog — There is a heavy blanket of fog enveloping everything.

The symbols shown appear on the fast travel map are shown regardless of whether you have c enabled or not. If you have cloud viewing enabled, clouds in the same position as the fog will obscure that fog. When in the midst of fog on the fast travel map, a small circle around your adventurer will blink to show the surrounding area.

Precipitation

Rain

It is raining.

Normal rain cleans any tile it lands on, removing blood, vomit and other bodily fluids on contact. Any dwarf caught outside when it rains will receive a minor unhappy thought.

When rain hits a tile labeled as a murky pool, it will begin to fill it up with 1/7 water, and if that does not evaporate the water will grow deeper, until the pool is full. Murky pools do not overflow from rain, but this extra water can be drained off and stored or used. (See the Well Guide.) While not much, it can really help maps without 'unlimited' water supplies such as rivers and brooks.

Snow and Cold

Winter is here.

A snow storm has come.

When water comes into contact with a freezing climate, such as winter months in a moderate biome, or at any time in a tundra or glacier, it will freeze into a wall of ice if at least 4/7 deep, or a floor otherwise. Freezing ice acts much like obsidian, and will instantly kill anything caught inside of it -- including creatures otherwise extremely hard to kill. In moderate biomes after winter has passed, ice will melt back into ponds. Ice walls will always thaw back into a full 7 units of liquid, regardless of the original water level, but ice floors will produce the original water depth when thawed. ^[1]

Dwarfs outside during a snowstorm can also freeze to death, so a very high priority when embarking on a glacier is to dig out some place warm for your idlers to rest.

Magma running under a snow-covered ground will melt it, but unlike ice, molten snow doesn't turn into water.

Evil weather

Certain evil surroundings feature freakish weather, such as fogs, clouds, and rains. They may afflict those caught in them with various kinds of syndromes or curses, such as poisonings or transformation into zombies. Names for evil weather are randomly generated, typically something along the lines of "abominable mist", "unholy gloom" (clouds) or "creeping murk", "horrid goo" (rain).

Two kinds of evil weather exist - evil rain and evil clouds. The type of weather effect and their associated syndromes (if any) are different and randomly chosen for every evil biome in a generated world. Usually there will be only one weather effect for a given evil biome, often in conjunction with the effect of corpse animation.

Evil Clouds

A cloud of haunting fog has drifted nearby!

Evil clouds are made of a generated inorganic gas or dust. They start in one tile and spread out in a similar manner to miasma vapor; when the game announces the cloud's presence, it will zoom into this tile. Evil clouds cause more serious syndromes than evil rains, similar to those of forgotten beasts, titans and demons. Certain evil clouds transform living beings caught in them into dangerous zombie-like thralls, turning them against all life while significantly increasing their strength and toughness attributes.

Evil clouds inflict worse syndromes than evil rains; thralling clouds are especially dangerous in the extreme, as the zombies produced are much stronger than those produced via ambient effects. These undead are very hard to kill and are much stronger than the unit they inflicted. Evil clouds have a tendency to roll over your outdoor trade depot and convert traveling merchants into a band of dwarf-hungry savages, which can be crippling to a fortress reliant on trade.

Thralling clouds are also dangerous in adventure mode. Undead status means hostility from civilized beings, reduced speed and no regeneration. However, other undead will ignore you.

Evil Rain

Evil rain can be made of either the blood of a civilized race (dwarves, goblins, etc.) or a randomly generated inorganic substance. Blood rain typically causes no syndromes, only giving whomever caught in it an unhappy thought. Generated substances are more dangerous, causing minor symptoms such as vomiting, blisters and fevers, as well as inspiring the aforementioned unhappy thought. Evil rain can also cause wounds and injure dwarves and other creatures caught in them, although the extent of injury depends on the substance. Dwarves spattered with evil rain will seek a bath after any outdoor work, wasting time and soap. There are rumors of rain composed of other substances, such as alcohol; however, this seems to be rare.

Dangers of evil weather

One of the dangers of evil weather is that ponds will never refill. Store water into underground basins and plan accordingly. Another annoyance is the total lack of wild bees in an evil climate. Though evil rains (excluding rains of blood) usually cause the "milder" types of syndromes, these may still cause death as a secondary result of that syndrome: e.g. suffocation from blisters, dehydration from chronic nausea.

Some evil weather effects condense on creatures, making their effects semi-permanent - symptoms won't go away until the source is washed. Those effects also can spread like a disease. In most cases, it will just infect dwarves that carry contaminated bodies to caskets. Thralling dust clouds, however, can quickly lead to an unstoppable zombie apocalypse if the dust is not completely washed off somehow.

Movement of evil weather and safeguarding

Evil weather forms on the edge of the map and moves about the screen in one direction as the wind blows. Because the clouds inflate similarly to miasma, they can very quickly dissipate, fly out of the map immediately, carry on at a steady pace, or spread rapidly engulfing very large areas. They will not, however, change direction.

Although it will glide along a single Z-level, it will climb straight walls and pass over structures. It will not move through a closed door or raised drawbridge, but it can descend from an open roof and it will pass through fortifications with ease. If you choose to fortify outside, be sure to have any open areas secured with floodgates to act as shutters to keep the clouds out. Adding doors throughout the structure to stop any accidentally contained clouds from moving further inward does not hurt.

Undead created by evil weather gain immediate strength bonuses and acquire a status of Opposed to Life. They will tirelessly seek out living things to kill until they are struck down, which can take considerable effort.