Mountain hazards key

Moderate or heavy dry falling snow (either continuous or in the form of frequent showers) with winds speeds of 30 m.p.h. or more and a reasonably extensive snow cover.

Near zero visibility and total disorientation likely.

Moderate or heavy dry falling snow (either continuous or in the form of frequent showers), lasting for at least 2 hours or more.

Significantly reduced visibility, potential danger with losing footing if paths are obscured. Navigation more difficult.

Winds with consistent gusts above 70 m.p.h.

Risk of losing one’s footing in gusts. Danger increased on exposed ridges.

Winds with consistent gusts above 50 m.p.h.

Considerable buffeting.

Cloud bases at or below 600 metres (500 metres for Peak District) for 2 hours or more.

Please note that on some high level plateaux, especially the Cairngorms, as well as on Ben Nevis, considerably higher cloud bases can be as hazardous.

Significantly reduced visibility resulting in major navigation difficulties.

Lightning strikes.

When lightning strikes are likely to cause danger, especially on exposed tops and ridges

When cooling is greatly increased by strong winds, normally exceeding 35 m.p.h. mean wind speed. If driving rain or sleet is also forecast winds may be lower than 35 m.p.h.   

Please note that other factors such as mist, sunshine, precipitation and snow cover will either mitigate or enhance cooling.

Considerable risk of hypothermia and frostbite, unless adequately equipped and protected.

Moderate or heavy rainfall lasting for at least 2 hours or more.

Risk of major discomfort unless adequately equipped and protected. Reduced visibility possible with risk of loosing footing on slippery paths/rocks. Risk that water levels in watercourses/rivers may rise rapidly.