Editing v0.31:Temperature

{{quality|Fine|08:00, 22 May 2010 (UTC)}}{{av}}

''For temperature as it relates to choosing an embarkation site, see [[DF2010:Climate|Climate]].''

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

[[Magma]]'s temperature is 12,000° Urist.

The highest possible temperature in Dwarf Fortress is 60,000°U - the temperature 60,001°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

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

|-
| Freezing Point of Water
| 10000
| 32
| 0
| 273.15
| 491.67

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

|-
| 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 {{L|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 10067.
</small>

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

==Melting point==

This is the temperature at which an object will melt. Any material with a melting (and ignite and heat damage) point over 12,000 °U is {{L|magma-safe}}.

==Boiling point==

This is the temperature at which an object will evaporate.

==Ignition point==

This is the temperature at which an object will catch fire, if at all. If it doesn't it is {{L|fire-safe}}.

==Heat damage point==

This is the temperature above which an object will begin to take {{L|wear|damage}}. Flammable items without a heat damage point (or with an exceptionally high one) will take damage very slowly, causing them to burn for about 9-10 months before disappearing.

==Cold damage point==

This is the temperature below which an object will begin to take {{L|wear|damage}}.

==Specific heat==

This determines how long it takes an object to heat up or cool down. An object with high specific heat will change temperature more slowly.

==Fixed temperature==

A substance's temperature can be forced to always be a certain value via the MAT_FIXED_TEMP {{L|material definition token}}.  The only standard material which uses this is the {{L|nether-cap}}, who's temperature is always at the freezing point.  If a substance's temperature is fixed to between its cold damage point and its heat damage point then items made from that substance will never suffer cold/heat damage, unless it's {{L|dump}}ed into {{L|magma}} or {{L|water}}.  This makes nether cap {{L|fire-safe}} and {{L|magma safe}}, in spite of being {{L|wood}}.

The fixed temperature of an item is set when the item comes into existence, so you can't change the MAT_FIXED_TEMP token to cause an existing item to melt/burn/etc.

The fixed temperature of a {{L|container}} has no effect on it's contents, so you can't freeze {{L|water}} by putting it into a {{L|bucket}} made from nether cap.

The fixed temperature of a substance only effects items made from that substance.  For example, setting a type of rock to have a fixed temperature over its melting point won't cause walls made from that rock to instantly melt, cause ice walls adjacent to the rock walls to melt, or even cause them to be considered [[warm stone]].