Weather

The GM rolls the weather once, at the start of each Wilderness Day, on the one-roll weather tables for the region's climate. Climate is a separate axis from terrain: any hex is a terrain plus a climate. There are six climates: Temperate (plains and Midwest; the default), Arid (desert and badlands), Polar (arctic and tundra), Tropical (jungle and humid lowlands), Highland (mountains and alpine) and Wetland (swamp and coast). The calendar and seasons follow the real-world year.

Each climate has six axes, rolled together in one throw: d20 Sky, d12 Temperature, d10 Wind, d8 Timing, d6 Foretelling and d4 Tomorrow. Timing and Tomorrow are shared by every climate. Some climates lean on particular Timing results for their signature weather: in Arid, "peaks at midday" is usually the heat; in Tropical, "arrives in the afternoon" is the daily storm; in Highland, "builds through the day, worst at evening" is the afternoon mountain storm.

The Sky die's bands sit in the same place in every climate: 16–18 Severe, 19 Extreme, 20 Aether-touched; only the split of 1–15 between Fair and Poor changes by climate.

Heat & Temperature Limits

Heat uses the G.R.A.P.H. scale (H1 Frigid, H2 Cold, H3 Normal, H4 Hot, H5 Extreme Heat), and its effects use the usual Exposure and Strain rules for that scale. The Temperature die shifts the season's baseline Heat by at most ±2 and can never push a hex below H1 or above H5 on its own. H0 and H6 need an exceptional cause: severe wind chill (a baseline of H1–H2 with a howling wind or an Extreme sky), an Aether event, or High Altitude combined with low pressure, high wind and winter. Some climates run nights one Heat step colder than the day (noted below). Winter clothing cancels severe cold's damage and reduces extreme cold's damage to that of severe cold.

High Altitude

High Altitude is a hex feature, not a climate: a Temperate or Arid mountain hex can have it. It lowers the hex's baseline Heat by 1 (still not to H0 on its own) and sets Pressure to P2 (Thin): sudden exposure gives 1 Disadvantage on physical checks until acclimated, which takes 24 hours (or is negated by a respirator, vacuum mask or e-suit). A full Wilderness Day at altitude acclimates the party. Anything higher (P1 Very Thin, above the treeline) is deliberately not covered: people can't really survive up there.

What the GM Reads

Wind, Timing, Foretelling and Tomorrow are read by the GM rather than turned into rules. Timing decides whether the worst of the weather falls on the Travel phase or the night's camp; wind affects things like a camp fire's smoke or ranged attacks; Foretelling gives the signs beforehand (what a Farmer's "Of the Land" feature reads).

Seasons

Each climate's baseline Heat by season, and what its precipitation and storm results become.

Climate Notes

• Arid: mostly clear skies, big swings between day and night, dust and flash floods instead of ordinary storms. Nights run one Heat step colder than the day.
• Polar: cold is the baseline and precipitation is almost always snow; the hazards are whiteout, ground blizzards, ice and exposure. The winter baseline of H1 is deliberate: unprotected exposure is deadly there, so Polar winter effectively requires cold-weather gear. Colder Temperature results do nothing more in winter (narration only), and H0 needs an exceptional cause. The warm results (10–12) aren't safe either: meltwater and rotten ice are hazards of their own.
• Tropical: heat sits high all year, with humidity, daily storms and cyclones. The H4 baseline is deliberate: the extreme-heat rules (double water, a Fortitude save when unprotected) make gear and water the defining problem. Some rain in the dry season is normal. Flash floods come with the Torrent and Downpour results and are handled by the GM as a hazard.
• Highland: fast changes, wind on exposed ground, lightning on the peaks. Elevation itself is the High Altitude feature, not this climate.
• Wetland: damp air, fog and storms off the water; the water steadies the temperature. Tides and flooding are hazards of particular hexes and of the Severe and Extreme results, handled by the GM like Highland avalanches.