JJThunder To The Max: Snow & Blizzard Fix

Makes JJThunder's mountains actually behave like mountains — snow by altitude, not by biome, plus a real blizzard that punishes climbing in a storm.

⚠️ Requires JJThunder To The Max

This is a dependency addon, not a standalone world-gen pack. It only edits biome files that JJThunder To The Max generates — without JJThunder installed and actively generating the world, this pack has nothing to patch and will do nothing.

This addon must load with higher priority than (be placed above) JJThunder To The Max in your datapack list, so its biome temperature overrides actually take effect instead of being overwritten by JJThunder's own biome files.

The Problem

JJThunder To The Max generates mountains nearly 1,900 blocks tall on a world that runs from Y -64 to Y 2032. But vanilla snow is tied to each biome's own temperature, not altitude — so you'd get a snowy taiga peak sitting right next to a bone-dry jungle peak at the exact same height. On mountains this scale, that stops looking like weather and starts looking like a bug.

The Fix

This pack normalizes the temperature of 31 biomes (forests, taigas, jungles, plains, swamps, underground biomes, stony peaks/shores, and more — JJThunder's molten biomes and frozen rivers are deliberately left alone) to one flat value. That cancels out each biome's "natural" snowline entirely, so snowfall becomes a function of how high up you are, not which biome you happen to be standing in — the way an actual mountain works.

On top of that, it adds a genuine high-altitude blizzard: past a certain height, storms stop being cosmetic and start being dangerous.

How It Plays Out

Elevation	Behavior
Y 0 – ~1232	Normal biome behavior — no snow, no debuffs
~Y 1232	Snowline begins — snow settles here regardless of biome
Y 1232 – 1844	Snowy alpine zone — cold and snow-covered, but perfectly safe
Y 1844+	Blizzard threshold — but only while it's actively precipitating
~Y 1900	Typical peak height for JJThunder's mountains
Y 2032	World height limit

Above Y 1844, while it's raining or snowing, every player up there gets, every tick:

Snowflake/cloud particle whiteout around them
Slowness II, continuously refreshed
Darkness, sustained (not pulsed) for a proper whiteout effect
1 damage every 3 seconds (frostbite)

Drop below Y 1844, or wait for the weather to clear, and every debuff cuts out immediately — nothing lingers.

The rule this creates: never start a summit push while it's raining. Clear-weather climbing above the snowline is cold but safe. Getting caught above 1844 during any precipitation turns the last stretch of the climb into a genuine survival threat — the intent is an Everest-style summit that's meant to be nearly impossible to actually stand on during a storm.

Compatibility & Installation

Requires JJThunder To The Max to already be generating the world — this pack only edits biomes JJThunder places, it doesn't add terrain itself.
Drop the zip into your world's datapacks folder like any other data pack.
Must be placed above JJThunder To The Max in your datapack list — see the notice at the top of this page.
Works alongside performance mods; overall order should be: performance mods → JJThunder To The Max → this fix (above JJThunder) → vanilla.
Like JJThunder itself, this needs to be applied to a new world — it won't retroactively fix terrain that's already generated.

License

Public Domain. Use it, modify it, redistribute it, no credit needed. This addon leans heavily on JJThunder To The Max's own biome files rather than starting from scratch — most of the underlying biome structure is copied straight from JJThunder. On top of that base, the temperature values across the 31 targeted biomes were tweaked so the snowline kicks in at a much lower altitude than JJThunder's defaults, and the blizzard system — particle effects, status effect application, and the per-tick altitude/weather checks that decide whether a player is standing in the blizzard zone — was built with Claude. I can't code for shi ngl...

Credits

JJThunder To The Max — world generation base, required dependency (not made by me):
🔗 https://modrinth.com/datapack/jjthunder-to-the-max

JJThunder To The Max Snow & Blizzard Fix