Seasons and Weather¶

Season Cycle¶

The Frontier Marches operates on a four-season year. Each season lasts one real calendar month. The seasonal clock advances at the start of each real-world month, synchronized to UTC.

Season	In-World Name	Meaning
Spring	Tulvakausi	Flood Season
Summer	Loimuaika	Flame Time
Autumn	Satokausi	Harvest Season
Winter	Kaamos	The Dark

The cycle repeats every four months. Server launch begins in Spring.

Season Transitions¶

A transition window of 48 hours (two settlement ticks) occurs at every season boundary. During this window:

New seasonal spawns begin appearing while outgoing seasonal spawns are still present
Seasonal board orders from the outgoing season remain valid until their listed expiry
Seasonal events may trigger for either the outgoing or incoming season

Player notifications: - 7 real days before a transition: season change card appears in the notification panel - 48 hours before: reminder notification with preview of incoming season effects - At transition: season change announcement on the town board and map overlay update

Spring — Tulvakausi (Flood Season)¶

World Effects¶

River Maren water level rises; ford crossings become impassable for wagon-class loadouts for 2 settlement ticks after the season opens
Flood plains and low marsh hexes become difficult terrain: movement cost +50%
Several dry-season shortcuts through river margins become inaccessible
Maarenvaki (drowned hollow) encounter probability increases significantly — flood season stirs the old river graves

Resource Effects¶

Spring herbs emerge: antler velvet (Kaaduaran), several Metsadu reagent plants, early berry patches
Fishing yield increases across all river zones (spring run)
Talmaes planting calendar begins — seed orders open on the branch board

Creature Effects¶

Kaaduaran (forest stag) migrates back to light forest from winter shelter zones
Bergulfr (mountain wolf) returns to mountain elevations from winter hill descent
Bergvargen (hill goblin raider) warbands pull back from road corridors to spring camp-building

Town Effects¶

Arujoki: Fish yield rises significantly; dock repair commissions open
Talmaes: Planting phase opens; field labor demand increases; work order board fills
Trevalkaan: Food band stabilizes after winter; medicine demand drops

Summer — Loimuaika (Flame Time)¶

World Effects¶

Maximum travel speed on open terrain (no movement penalty modifiers)
Coastal zones and high mountain passes become accessible (cleared of snow and mud)
Karst cave systems at their driest — cave exploration carries the lowest weather complication risk

Resource Effects¶

Peak herb yield across all zones; Metsadu supply at maximum
Suohauki and Suopuli at their most active — marsh resources at peak but encounter risk is highest
Logging at maximum yield; Coedwair's timber output highest in summer
Bog dye plants and summer-only mushroom species spawn in dense forest (short harvest windows)

Creature Effects¶

All creature families at their standard spawn distribution — no seasonal modifiers
Briar Thicket growth pressure on Metsadu highest — thicket-clearing commissions multiply on the branch board
Mountain zones accessible to players with Routefinding at Practiced or above; Tunturikat and Bergulfr fully active in their territory

Town Effects¶

Rumiarr: Peak quarry output; stone and mineral prices dip slightly
Metsadu: Maximum reagent supply; Physician and Alchemist service costs drop to base rate
Trevalkaan: Maximum merchant traffic; market price index at its most competitive

Autumn — Satokausi (Harvest Season)¶

World Effects¶

Leaf cover in forests reduces effective Tracking skill by one band for route-following (dense ground cover obscures prints in dense forest and light forest biomes)
First cold weather arrives — mountain pass access begins to narrow; cold gear check activates for mountain expeditions
Rut season begins for Kaaduaran — rutting stags actively aggressive in forest zones

Resource Effects¶

Grain harvest at Talmaes — harvest rush board opens (time-limited, Headman Bathrys)
Forest foraging at peak yield for nuts, autumn fruits, and mushrooms
First cold-weather hides available (Bergulfr winter coat, Tunturikat full coat)
Stag antler rack at maximum size before rut — antler material quality peaks; antler velvet window closes

Creature Effects¶

Kaaduaran: Rutting males escalate from D to C encounter rank; hind groups remain at normal
Bergvargen (hill goblin raiders): Raiding season opens — warbands push toward road corridors and farmland margins; Polheen security board peaks
Peltorotta (field rat): Infestation probability at Talmaes reaches its highest point as harvested grain enters storage

Town Effects¶

Talmaes: Highest seasonal food output; grain prices briefly lower; preservation contract board opens
Polheen: Caravan traffic peaks before winter; Customs Warden Lowaan posts maximum security orders
Trevalkaan: Board most active; food preservation orders and cold gear fabrication contracts arrive in volume

Winter — Kaamos (The Dark)¶

World Effects¶

Snow and ice in mountain zones: Routefinding at Skilled required to navigate safely (failure triggers expedition time extension plus injury risk)
Mountain passes fully closed to solo or under-equipped players (Routefinding below Skilled generates a block warning at expedition confirmation)
Upper River Maren sections freeze: some routes impassable in flood season become walkable on ice, but with ice travel risk (fall-through event possible without Waterfinding at Practiced)
Cold gear requirement enters the resolver — characters without adequate cold protection suffer Exhaustion at an accelerated rate on cold-tile expeditions (see Cold Gear table below)

Resource Effects¶

Most herb patches dormant — only winter-specific species active (cold-weather medicinal bark, ice fungus near karst drainage points)
Fishing continues through ice on frozen sections; lower yield but Arujoki's expertise keeps operations running — Arujoki's winter fishing board remains open throughout
Timber harvest continues — dry frozen wood easiest to process
Bergulfr winter pelts at maximum quality (undercoat fully developed)

Creature Effects¶

Bergulfr: Descends from mountain elevations; active in rocky hills and hill grassland; Rumiarr and Trevalkaan winter alert boards activate
Goblinoids: Bergvargen returns to camp; Kivipiika remains in caves; overall goblinoid board volume drops
Undead: Barrow site activity increases — Kaamos is the traditional period of the dead, and event probability for undead stirring events peaks
Tapiokarhu (bear): Enters reduced activity; encounter probability halved; den intrusion risk elevated (bears disturbed in winter are more aggressive than summer)

Town Effects¶

Arujoki: Food supply tightens; ice fishing supplements reserves
Talmaes: No active harvest; relies on stored grain — granary security board peaks
Rumiarr: Mine operations continue; cold gear demand from miners spikes
Trevalkaan: Food price index climbs; medicine pressure from winter illness events; cold-weather equipment is the most active market category

Cold Gear System¶

When an expedition enters cold-tile terrain (mountain in winter, high rocky hills during blizzard) the resolver evaluates the character's cold protection level.

Cold Protection Level	How Provided	Resolver Effect
None	No insulated outerwear equipped	Exhaustion status applied after first encounter step
Partial	Standard armor without cold lining	Exhaustion delayed to second encounter step
Adequate	Cold-weather lining on armor, or standard cold-weather cloak	No Exhaustion from cold; normal resolver applies
Superior	Exceptional cold armor or specialist winter cloak	Cold terrain movement penalty halved; Exhaustion immune for this expedition

Cold protection is provided by leatherworked outerwear linings — bear pelts, Tunturikat lynx lining, Bergulfr winter coat — crafted through Leatherworking at appropriate tier. Cold-Weather Cloaks (see frontier-marches-crafting.md) are the standard layered solution for players who want cold protection without replacing full armor.

Weather¶

Weather is distinct from seasons. Seasons determine weather probability distributions; weather itself is a randomized per-tick state applied to each area tile.

Weather Generation¶

Each settlement tick, each area receives a weather evaluation:

Season baseline weather probability table is read
Local area modifiers apply (elevation, river proximity, active events)
Weather for the current tick is published to the map layer

Players see weather icons on map tiles before confirming expeditions. Weather is part of the legible preparation context — surprises are possible but the information is available if the player checks.

Weather Types¶

Weather	Primary Biomes	Mechanical Effects
Clear	All	No modifier
Overcast	All	No modifier (atmospheric only)
Rain	Plains, farmland, light forest, marsh	Movement cost +10%; Tracking improved in open terrain (wet ground shows prints); Tracking reduced in dense forest (floor obscured)
Heavy Rain	Plains, marsh, river corridors	Movement cost +25%; wagon crossings blocked at fords; surprise encounter probability up in dense cover
Fog	Marsh, river, plains, karst	Tracking range reduced; map reveal radius reduced on survey steps; surprise encounter probability increased
Snowfall	Mountain, rocky hills, hill grassland (winter)	Movement cost +15%; cold gear check activates
Blizzard	Mountain (winter); rocky hills (severe winter)	Expedition blocked unless Routefinding at Skilled and adequate cold gear equipped; expeditions already in blizzard zones take automatic Exhaustion
River Surge	River corridors, low plains (spring peak)	Ford crossings blocked for 1 tick; low-ground hexes flooded; Maarenvaki encounter probability elevated
Heatwave	Plains, farmland, karst scrubland (summer)	Water consumption rate doubles; Exhaustion risk on long expeditions in exposed terrain; Endurance threshold check activates
Wildfire Risk	Dense forest, light forest edges (summer dry)	Coedwair wildfire event may trigger; logging suspended; firebreak board opens

Season × Weather Probability Guide¶

Weather	Spring	Summer	Autumn	Winter
Clear	30%	50%	35%	20%
Overcast	25%	20%	30%	25%
Rain	25%	10%	20%	5%
Heavy Rain	10%	5%	8%	2%
Fog	5%	3%	5%	8%
River Surge	5%	0%	0%	0%
Snowfall	0%	0%	2%	25%
Blizzard	0%	0%	0%	10%
Heatwave	0%	8%	0%	0%
Wildfire Risk	0%	4%	0%	0%

Probabilities are per area per tick; area type modifiers (elevation, river proximity) shift the distribution before the roll.

Weather and Expedition Planning¶

Weather is visible on the map before commitment. Players who check the map before sending an expedition see the current tick's weather on their target area. They do not see next-tick weather — some uncertainty is preserved.

Board orders with weather dependencies (e.g., Talmaes harvest rush before the storm arrives, Arujoki dock repair before the river surge hits) communicate urgency through the order's expiry window and the visible weather icon — not through hidden countdowns.