How to Start a Fire in the Rain: Wet Weather Fire Guide

Why is it so hard to start a fire in the rain?

Water is the enemy of fire because it steals heat. Before wet wood can reach its ignition temperature of roughly 250–300 °C, all the water in and on it must first be heated and evaporated, and evaporating water takes a great deal of energy. A small tinder flame simply cannot supply enough heat to dry soaked kindling and ignite it at the same time. Rain also cools the flame directly, and wet ground draws heat from the base of the fire.

The good news: rain soaks the surface of wood much faster than its interior. A dead branch that has been rained on for a day is wet on the outside and in its outer millimetres, but dry inside. Thin twigs, leaves and wood lying on the ground are another matter: they are saturated. The whole strategy for wet-weather fire follows from this: find thicker dead wood that is off the ground, split it open, and protect the dry wood you have exposed.

Prepare before the rain arrives

The easiest wet-weather fire is the one you prepared for. If rain is forecast, collect tinder and kindling while it is still dry and store it under your tarp or in a bag. Pocket a handful of dry birch bark or dry grass during the day whenever you see it. Carry at least two ignition sources, because matches and ferro rods have different weaknesses: a ferro rod works when wet but needs fine tinder, while a lighter provides a sustained flame but can fail when cold or wet.

Your kit matters too. A good saw and knife let you reach the dry core of thicker wood; a tarp lets you work and light the fire out of the rain. Check our bushcraft kit list and plan the right fire kit with the Kit Builder.

Allow enough time, too. In the wet, finding wood, splitting and lighting can easily take 45 minutes, and in autumn and winter it may be dark by then. The sunset and daylight calculator shows when you should start at the latest. Splitting wood in the dark with cold, clumsy fingers is slow and considerably raises the risk of injury.

How to find dry wood in the rain

Finding dry fuel is the most important skill for fire in wet weather. Look up and look inside, not down. These are the best sources, roughly in order of reliability:

Dead standing wood

Dead branches still attached to trees, and small dead trees that are still upright, shed rain and dry quickly in the wind. Even after long rain, their core is dry. A dead branch that snaps with a crack is usable; one that bends or feels spongy is not.

Dead lower branches of conifers

Spruce and pine drop their lower branches as they grow. The thin, dead, grey twigs close to the trunk under a dense canopy are often surprisingly dry and make excellent fine kindling. Snap them off close to the trunk, only from dead branches.

Fatwood and birch bark

Resin-rich fatwood from old pine stumps repels water and lights even when damp. Birch bark contains oily compounds that burn even when wet; peel it from dead, fallen birches, never from living trees. Both are the best natural tinder for rain.

Sheltered spots

Wood under overhanging rocks, beneath the lean of a fallen trunk, inside hollow stumps or under dense spruce often stays drier. The underside of a leaning dead log may be dry even when the top is soaked.

The snap test: bend a finger-thick dead stick. A clean, sharp crack means it is dry enough inside to use. If it bends, tears with a dull sound or feels cold and heavy, leave it. Train this on every walk in the rain and you will soon collect a good bundle in a few minutes.

Splitting wood to reach the dry core

Splitting is the heart of any rain fire. The thicker the dead wood, the larger its dry core. Wrist-thick to calf-thick pieces are ideal: thick enough to be dry inside, thin enough to process with a knife and baton. Cut them to length with a folding saw, split them with an axe or by batoning your knife, and keep splitting until you have a range of sizes.

What it should look like: freshly split faces are pale and feel dry, or at most cool, against your lips or the back of your hand. If even the core is dark and wet, the wood was rotten or lay on the ground: find another piece rather than trying to burn it.

Work on a dry surface such as a board, a piece of bark or your pack lid, not on the wet ground. Dry your hands on the inside of your jacket before handling tinder. The wet outer pieces of each log are not wasted: stack them near the fire later so they dry out and become fuel.

Choosing and sheltering the fire site

In rain, the fire site needs protection from above and below. From below, wet ground drains heat; from above, raindrops cool the young flame and soak the kindling.

Build a platform

Lay a platform of wrist-thick dead sticks tightly side by side, ideally in two crossing layers, or use a flat, dry stone. It lifts the tinder off the wet ground and lets air in from below. On snow, the platform is essential. More on platforms in our overview of fire lays.

Shelter from rain

A tarp pitched high above the fire site keeps rain off while you light and establish the fire. Keep at least 2 m of height between the fire and a synthetic tarp and pitch it at an angle so smoke can escape; lower it only while you light a small tinder bundle, then raise it. Natural cover also helps: the lee of a large boulder, a dense spruce canopy or an overhang. Watch for dead branches above you, which can fall in wind and rain. The site selection guide covers these hazards.

Shelter from wind

Rain rarely comes alone. Wind blows rain into the fire and carries heat away. Build on the lee side of a log, rock or bank, or set up a lean-to fire lay with a windbreak log. A small, sheltered fire is better than a big exposed one.

Fire extenders: tinder that burns longer

In rain, your tinder flame has to burn long enough to dry and ignite damp kindling. A few seconds are rarely enough. Fire extenders are materials that burn for a minute or longer and bridge that gap. Natural extenders can be found in the forest; carried extenders are cheap insurance in your kit.

Building and lighting a fire in wet weather

Build a compact fire lay on your platform: a small teepee or a lean-to against a windbreak log works best. Pack it more tightly than in dry weather so the pieces heat each other, but leave enough gaps for air. Prepare two to three times more fine kindling than usual, because some of it will only dry and not burn at first.

Light the fire low on the windward side so the wind pushes the flame into the kindling. Shield the young flame with your body or hat. When the tinder flares up, do not rush: add matchstick kindling first, a few pieces at a time, and wait until each layer burns before adding the next. Blowing gently at the base helps a struggling fire, but blowing too hard scatters the embers. Resist the temptation to add thick wood early; it smothers the flame and sends clouds of steam and smoke up.

How to keep a fire going in the rain

Once the fire burns, your goal is a bed of hot coals. Coals store heat, dry the wood you add and keep the fire alive through heavy showers. A fire that is only flames and no coals will die the moment the rain gets heavier.

• Dry your next wood by the fire. Stack fuel on its end around the fire, or build a small drying rack, and rotate pieces so they steam dry before you feed them.
• Feed split wood. Split faces dry and catch much faster than round branches with wet bark.
• Feed small and often. Several small pieces burn better than one large wet log.
• Create a roof of fuel. In a log cabin or teepee lay, larger pieces over the top shed some rain from the core while drying out.
• Use hardwood for coals. Once the fire is established, dense hardwood like oak or beech builds a longer-lasting coal bed than softwood.
• Keep the fire tended. In heavy rain someone should stay with the fire; a neglected fire drowns quickly.

How much wood do you need? A fire in rain consumes more wood than in dry weather because part of the energy goes into drying. The firewood calculator gives a baseline; add a generous margin for wet conditions. If the rain turns cold and windy, check the wind chill calculator and put on dry layers before you get chilled: hypothermia is a real risk in cold rain, even above freezing.

When the fire will not catch: troubleshooting

Wet-weather fires fail for a handful of reasons. Before you use up all your tinder, stop, look and work through the questions below.

If everything fails and conditions are dangerous, prioritise staying warm and dry: shelter, dry clothing, insulation and food come first. A fire is valuable, but hypothermia is prevented by keeping dry and insulated. Once the fire has served its purpose, extinguish it completely: see campfire safety. Explore all fire skills to build a full toolkit.