Wind & Beaufort Camp Calculator

How to use the wind and Beaufort calculator

1. Enter the mean wind from the forecast in km/h. If your forecast gives metres per second, multiply by 3.6; if it gives knots, multiply by 1.85.
2. Enter the gusts. Most forecasts list them separately. Enter 0 if you do not know them – the calculator then reminds you that gusts can be much stronger than the mean wind.
3. Choose where you camp: valley, forest or lowland, or ridge, summit or open plateau.
4. Choose your shelter: tent, tarp or hammock.

The result shows the Beaufort level of the mean wind and of the gusts (with the speed in m/s and the gust factor), the level to plan your camp for, what that level means at camp, a card for your shelter and one for your fire, and the Beaufort scale for campers with your row highlighted.

Worked examples

25 km/h, gusts 45 km/h, tarp in the valley

A typical blustery autumn forecast. The calculator returns:

• Mean wind: Bft 4 – moderate breeze, 25 km/h, 6.9 m/s
• Gusts: Bft 6 – 45 km/h, 12.5 m/s, ×1.8 the mean wind
• Plan camp for: Bft 5, rated from the gusts
• At camp: tarp edge to the wind; keep the fire small or skip it
• Tarp: low A-frame or lean-to with the closed edge to the wind; re-tension after the first gusts
• Fire: keep the fire small or skip it; use a stove in the lee instead

The gusts are two levels above the mean wind, so the tool adds a tip: pitch for the gusts, not for the forecast average.

The same forecast on a ridge

Move the same tarp up to an open ridge and the camp level rises to Bft 6 (+1 level for high ground). Now the advice is a storm pitch close to the ground, short guylines and no open sides to the wind – or a sheltered spot further down – and no open fire: cook on a stove in a sheltered spot, never inside a tent.

35 km/h, gusts 60 km/h, hammock in the forest

Mean wind Bft 5 (fresh breeze, 9.7 m/s), gusts Bft 7 (16.7 m/s, ×1.7), plan camp for Bft 6, rated from the gusts. The hammock card is blunt: trees are the danger now – move to the ground away from tall trees, or leave the forest.

Three more cases

On a ridge at Bft 8+ the honest answer is usually to go down.

How it is calculated

The mean wind and the gusts are rounded to whole km/h and placed on the Beaufort scale: 0 below 1 km/h, 1 at 1–5, 2 at 6–11, 3 at 12–19, 4 at 20–28, 5 at 29–38, 6 at 39–49, 7 at 50–61, 8 at 62–74, 9 at 75–88, 10 at 89–102, 11 at 103–117 and 12 from 118 km/h.

The camp level is the mean-wind level or one level below the gust level, whichever is higher. The weather guide says only that gusts can be much stronger than the average wind; turning that into “gust level minus one” is a conservative assumption of this calculator, not a published rule. On a ridge, summit or open plateau one more level is added. The guide says wind there is often one or two Beaufort levels higher than in the valley; the calculator uses the lower end of that range, so on a very exposed site plan for more.

The camp meanings for levels 3 to 8+ are those of the Beaufort table for campers in the weather guide; levels 0–2 are short notes of this tool. Everything from Bft 8 upwards gets the 8+ advice.

Fire and wind

The fire card follows the camp level. Up to Bft 3 the fire is manageable – the usual distances and any local fire bans still apply: at least 5 m from tents and hammocks and at least 3 m from synthetic tarps. At Bft 4 sparks travel further, so keep the fire small on cleared ground with water at hand and leave a longer distance downwind. At Bft 5 keep it small or skip it and use a stove in the lee. From Bft 6 there is no open fire at all. Why wind is the most underestimated fire danger is explained in campfire safety.

What the calculator cannot tell you

• Your exact wind. Forecast wind is measured 10 m above open ground. In a forest it is weaker, behind a boulder weaker still, in a saddle or gap between hills often stronger.
• The trees above you. The main danger in a storm is what the wind brings down. Dead trees, hanging branches and shallow-rooted trees on soaked ground fall first – check for widowmakers before you pitch.
• Thunderstorm gusts. A storm cell can bring sudden gusts far above the forecast. If you hear thunder, use the thunderstorm distance calculator and act on it.
• Cold. Wind makes you cold long before it damages your shelter. The wind chill calculator shows the feels-like temperature.

Safety margin: the Beaufort scale is a rough guide for inland terrain, not a safety rating. Terrain, tree health and rain-soaked ground matter as much as the number. When a storm warning is out for your area, many forestry services advise staying out of woodland during the storm and for some time afterwards.

Practical tips for a windy camp

• Choose the site before the shelter: the lee of a low ridge, a dense hedge or a boulder beats any pitch on open ground. Our guide to camping in wind covers site, pitch and night routine step by step.
• Pitch your tarp low with the closed edge to the wind; an A-frame or lean-to is calmer than a flying wing.
• Point the narrow, low end of a tent into the wind and peg the windward side first.
• In a hammock, pull the tarp low and close; wind underneath cools you fast, so use an underquilt or pad.
• Re-check guylines and pegs before dark and after the first strong gusts – cord stretches and fabric settles.
• Wind often changes direction with a front. Watch the sky and read the signs in reading the weather.