Editing v0.34:Temperature

{{quality|Fine|15:51 27 December 2011 (UTC)}}{{av}}

''For temperature as it relates to choosing an embarkation site, see [[Climate]].''

==Temperature scale==
Dwarf Fortress uses its own temperature scale in most cases, often called "Degrees [[Main:Urist|Urist]]" on this wiki.
So if you see something like [HOMEOTHERM:10067], don't be amazed.

[[Magma]]'s temperature is {{ct|12000}}.

The highest possible temperature in Dwarf Fortress is {{ct|60000}} &mdash; the temperature 60001&nbsp;°U is used internally for temperatures which have been set to "NONE".

===Conversion===

[DF scale] = [FAHRENHEIT] + 9968

[DF scale] = [CELSIUS] * 9/5 + 10000

[DF scale] = [KELVIN] * 9/5 + 9508.33

[DF scale] = [RANKINE] + 9508.33

''(Note: Mod-makers may find this [http://www.bay12forums.com/smf/index.php?topic=80523.0 Temperature Conversion Utility] handy if they find themselves having to convert a lot of temperatures to and/or from Degrees Urist.)''

===Reference Chart===

{| {{prettytable}}
|- bgcolor="#ddd"
! Significance
! DF Scale
! Fahrenheit
! Celsius
! Kelvin
! Rankine

|-
| Boiling Point of Water
| 10180
| 212
| 100
| 373.15
| 671.67

|-
|Human Body Temperature
| 10066.6<sup>2</sup>
| 98.6
| 37.0
| 310.15
| 558.27

|-
| [[Water#Freezing point|Freezing Point of Water]]
| 10000
| 32
| 0
| 273.15
| 491.67

|-
| Absolute Zero
| 9508.33<sup>2</sup>
| -459.67
| −273.15
| 0
| 0

|-
| DF Scale's Zero<sup>1</sup>
| 0
| -9968
| -5555.555...
| -5282.40555...
| -9508.33
|}

<small>
:<sup>1</sup>: Yes, temperatures in Dwarf Fortress can go '''far, far''' below absolute zero, which is physically impossible. Considering Dwarf Fortress also allows [[water wheel#Perpetual motion|perpetual motion]], it's best not to ask questions.
:<sup>2</sup>: Technically, fractional/decimal temperatures are not possible in Dwarf Fortress, as they are stored as unsigned 16-bit integers. For instance, body temp for humans in the raws is rounded to {{ct|10067}}.
</small>

Some general information about temperatures in DF (copied from somewhere on the forums):
{| class="wikitable"
|-
! Event / location
! Temperature
|-
| alcohol freezes
| {{ct|9850}}
|-
| water freezes
| {{ct|10000}}
|-
| underground
| {{ct|10015}}
|-
| outside (varies)
| {{ct|10048}}
|-
| dwarf/human body temp
| {{ct|10067}}
|-
| floor above magma
| {{ct|10075}}
|-
| fat melts
| {{ct|10078}}
|-
| water boils
| {{ct|10180}}
|-
| material is fire-safe
| {{ct|11000}}
|-
| common stone melts
| {{ct|11500}}
|-
| burning item (max)
| {{ct|11640}}
|-
| magma
| {{ct|12000}}
|-
|}

==Melting point==

This is the temperature at which a liquid material will freeze, or a solid material will melt. In Dwarf Fortress, the melting point and freezing point coincide exactly &mdash; this is contrary to many real-life materials, which can be supercooled.

==Boiling point==

This is the temperature at which the material will boil or condense. Water boils at {{ct|10180}}.

==Ignition point==

This is the temperature at which the material will catch fire.

==Heat damage point==

This is the temperature above which the material will begin to take heat [[wear|damage]]. Burning items without a heat damage point (or with an exceptionally high one) will take damage very slowly, causing them to burn for a very long time (9 months and 16.8 days) before disappearing.

==Cold damage point==

This is the temperature below which the material will begin to take frost [[wear|damage]].

==Specific heat==

This determines how long it takes the material to heat up or cool down. A material with a high specific heat capacity will hold more heat and affect its surroundings more before cooling down or heating up to equilibrium.

==Fixed temperature==

A material's temperature can be forced to always be a certain value via the MAT_FIXED_TEMP [[material definition token]].  The only standard material which uses this is [[nether-cap]] wood, whose temperature is always at the melting point of water.  If a material's temperature is fixed to between its cold damage point and its heat damage point, then items made from that material will never suffer cold/heat damage.  This makes nether-caps [[fire-safe]] and [[magma-safe]] despite being a type of [[wood]].

Due to the way fixed temperature is handled, giving a material a fixed temperature will not cause its actual temperature to change accordingly &mdash; instead, its temperature will simply be permanently locked at whatever it was previously. Removing a material's fixed temperature, however, will cause all items made of it to heat or cool until reaching equilibrium with their surroundings.

The fixed temperature of a [[container]] does affect its contents, but you can't freeze [[water]] by putting it into a [[bucket]] made from nether-cap because water will not freeze until it cools ''below'' {{ct|10000}}.

The fixed temperature of an inorganic material has no effect on unmined walls made from that material, though boulders '''will''' take on that temperature as they are produced via mining.