v0.31:Temperature

From Dwarf Fortress Wiki
Revision as of 15:26, 9 May 2014 by Quietust (talk | contribs)
(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to navigation Jump to search
This article is about an older version of DF.

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

Temperature scale[edit]

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[edit]

[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 Temperature Conversion Utility handy if they find themselves having to convert a lot of temperatures to and/or from Degrees Urist.)

Reference Chart[edit]

Significance DF Scale Fahrenheit Celsius Kelvin Rankine
Boiling Point of Water 10180 212 100 373.15 671.67
Human Body Temperature 10066.62 98.6 37.0 310.15 558.27
Freezing Point of Water 10000 32 0 273.15 491.67
Absolute Zero 9508.332 -459.67 −273.15 0 0
DF Scale's Zero1 0 -9968 -5555.555... -5282.40555... -9508.33

1 - Yes, temperatures in Dwarf Fortress can go far, far below absolute zero, which is physically impossible. Considering Dwarf Fortress also allows perpetual motion, it's best not to ask questions.
2 - 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.

Some general information about temperatures in DF (copied from somewhere on the forums):

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
material is fire-safe 11000 U
common stone melts 11500 U
burning coal (max) 11640 U
magma 12000 U
titan/forgotten beast fire 14000 U
dragon fire 50000 U

Melting point[edit]

This is the temperature at which the material will melt.

Boiling point[edit]

This is the temperature at which the material will evaporate.

Ignition point[edit]

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

Heat damage point[edit]

This is the temperature above which the material will begin to take heat 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[edit]

This is the temperature below which the material will begin to take frost damage.

Specific heat[edit]

This determines how long it takes the material to heat up or cool down. A material with a high specific heat capacity will change temperature more slowly.

Fixed temperature[edit]

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 - 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 10000 °U .

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.