Weather

Weather comes in fronts that drift across the sea with the wind. What a front brings depends on the ground under it: the same front rains on a temperate island, snows on a cold one in winter, raises dust over an arid one and drops ash on a volcanic one. Raid sites share the weather of the place they stand; underground and indoors there is none.

Fronts

• Fronts are born aimed at an island, more often in wet seasons and on wet islands (see seasons). Across a world there are about 5.4 new fronts a day, and a few alive at a time.
• A front lives 8–20 in-game hours: it builds up, passes over its island around the middle of its life and fades out downwind.
• It is 150–380 tiles across in radius, strongest in its core, and moves at 20–45 tiles an in-game hour along the day’s wind, faster in autumn and winter and slowest in summer.
• Strong fronts are rarer than weak ones. Where two fronts overlap, the stronger one sets the weather.

What falls

Front strength	Normally	Where the air is below 0.5 °C	Arid islands	Volcanic islands
below 5%	Nothing	Nothing	Nothing	Nothing
5%–35%	Drizzle	Snowfall	Dust storm	Ash fall
35%–75%	Rain	Snowfall	Dust storm	Ash fall
75% and up	Thunderstorm	Blizzard	Dust storm	Ash fall

Fog

Fog is local, not a front. On 60% of mornings (more on wet islands) a fog rises around 04:30, is thickest at 07:00 and is gone by 09:30. Swamps are foggy at night and in the morning, and fog also lingers for about 2 hours after rain.

Lightning

In a thunderstorm lightning flashes now and then (a 35% chance every 40 game seconds at full strength) and lights up the night for a moment.

What weather does

Weather affects everyone the same: you, zombies, soldiers and animals see and hear less in it. The table shows each kind at full strength compared with clear weather.

Weather	Sight	Hearing	Footstep noise	Speed	Soaks you	Air
Drizzle	90%	90%	85%	—	30%/h	−1 °C
Rain	80%	80%	70%	—	100%/h	−2 °C
Thunderstorm	60%	60%	50%	95%	160%/h	−4 °C
Fog	30%	95%	—	—	5%/h	−1 °C
Snowfall	70%	90%	80%	92%	35%/h	−2 °C
Blizzard	35%	60%	50%	85%	60%/h	−6 °C
Dust storm	40%	70%	60%	90%	—	—
Ash fall	55%	90%	80%	—	—	−1 °C

• Sight is how far everyone sees. Fog and blizzards cut it hard, which also makes it easier to sneak past enemies.
• Hearing is how far sounds carry to the listener; footstep noise is how loud your own steps are. Rain and storms cover your movement.
• Soaks you: while you are out in rain or snow without shelter you get wet at this rate. Being wet chills you; you dry off in shelter or by a fire (see survival).
• Air: the weather makes the air this much colder.
• The sky darkens too: a thunderstorm lets through 50% of the daylight, a blizzard 55%.

Wind

• The wind blows from a new direction each day. It is about 1.5 tiles a second when calm and up to 12 in a front, scaled by the season (spring 1×, summer 0.7×, autumn 1.3×, winter 1.5×).
• Wind chill: wind makes the air colder, by up to 8 °C in a strong wind.
• Bullets, arrows and grenades drift a little with the wind over long distances.
• Pollution drifts downwind (see pollution). Calm summers let smog build up.

Rain, snow and pollution

Rain washes pollution out of the air into the ground and the water: a steady rain clears about 6% of it an in-game hour. Falling snow and snow on the ground hold pollution instead, and let it go when they melt.

Wet ground and puddles

Rain wets the ground; puddles form where it has rained a lot and dry out over the next hours (faster when it is warm). Snow piles up on the ground while it snows and melts above 0 °C.

Snow on the ground

Snow slows you to 92% of your speed and your footsteps are 85% as loud; in deep snow 80% and 60%. Footprints show in fresh snow for about 2 in-game hours, less while it snows.

The forecast

A Field Radio picks up the weather forecast and shows the fronts on your map. See the map.