How Climate Works

Townstead works out the air temperature at every place from one climate model. Villagers, crops, rooms and thermometers use it, and players feel it through the temperature mod. See Temperature Mods.

The climate model runs only when a temperature mod is installed: Legendary Survival Overhaul, Cold Sweat or Tough As Nails. Without one, Townstead has no temperature. Crops grow as in vanilla, and the Pheno climate values read the vanilla biome temperature.

This section is for pack authors. For the player’s view, see Climate.

The Parts of the Climate

Part	What sets it	Page
Yearly mean	The biome’s profile, from real climate data. Plains average about 12 °C over the year.	Biome Profiles
Seasons	The biome’s profile, or its climate zone, sets the size of the swing. A season mod sets the time of year.	Seasons & Calendars
Day and night	The climate zone sets the range. Rain and cloud make it smaller.	Climate Zones
Weather	Rain cools the air by evaporation, more in dry air. Falling snow and lying snow have their own rules.	Climate Settings
Altitude	Air gets colder above sea level.	Climate Settings
Dimension	A dimension can use biome climates or one fixed temperature.	Dimensions
Underground	Under natural terrain, the air moves toward the ground temperature. Deep rock and buried lava are warm.	Underground
Rooms	An enclosed space has its own air temperature.	Temperature
Local heat	Fires, stoves and ice near a position warm or cool it. Pheno fields can add a local climate.	Pheno

How Townstead Calculates the Air

For a position outside any room, Townstead does these steps in order:

1. Take the yearly mean of the biome, then subtract the altitude cooling.
2. Add the seasonal swing for today’s date. With no season mod, this is zero.
3. Add the day and night curve for the time of day.
4. Add the rain cooling. Then apply the snow rules.
5. Blend toward the ground temperature when natural terrain covers the position.
6. Add nearby heat and cooling sources, and any Pheno local climate.

In a TerraFirmaCraft world, TerraFirmaCraft’s own temperature replaces steps 1 to 3. See TerraFirmaCraft Worlds.

Inside a room, Townstead uses the room’s own air temperature. The room exchanges heat with the outdoor air from step 4 and with the ground below it.

Example: Temperate Plains

The plains biome is in the temperate zone. With a season mod installed, plains air goes from about 0 °C on a clear winter night to about 25 °C on a summer afternoon. With no season mod, every day is a mild growing-season day: about 13 °C before sunrise and about 22 °C in the afternoon.

Use /townstead climate year minecraft:plains to see the full year. See Testing & Commands.

Data Files

File	What it controls	Page
data/<namespace>/climate/biome/<path>.json	One biome’s climate, from real data.	Biome Profiles
data/<namespace>/climate/zone/<id>.json	One climate zone, for biomes without a profile.	Climate Zones
data/<namespace>/climate/derivation.json	How biomes with no zone tag get a zone.	Climate Zones
data/<namespace>/climate/dimension/<id>.json	The climate of one dimension.	Dimensions
data/<namespace>/tags/worldgen/biome/climate/<zone>.json	Which biomes are in a zone.	Climate Zones
data/<namespace>/tags/block/crops/climate/<class>.json	Which crops are in a crop climate class.	Crops
data/townstead/need/temperature.json	Means, weather, snow, ground and crop numbers.	Climate Settings

Pheno

Pheno can read the climate and change it locally:

• The pheno:climate condition tests the zone, the time of year, snow and the air temperature. See Conditions.
• The pheno:air_temperature and pheno:climate values read numbers from the climate. See Selectors & Values.
• climate_offset_c on pheno:cloud makes a field that warms or cools the air inside it, for every temperature mod. See Actions.