Wind Show More
Little wind or walking hardly affected by the wind. 10-15mph or less.
Moderate breeze, fairly small impact
A noticeable breeze, locally may be gusty, but unlikely to affect progress. 15-25mph.
Windy, walking impeded
Blustery conditions, enough to give buffeting on higher terrain or affect balance on exposed ridges. 25 to 35mph.
Gale force, walking arduous
Considerable buffeting, walking into the wind will be strenuous on exposed terrain, stronger gusts may knock you off your feet. 35 to 55mph.
Severe gale or storm, mobility very difficult
Severe conditions on the mountains, any movement very challenging, you may be blown over. 55-70mph+
Visibility Show More
Excellent or superb visibility, no navigation issues.
Clear over snow cover
Excellent or superb visibility, but be aware that paths may be obscured by lying snow.
Very murky conditions, the mountains shrouded in fog, making navigation challenging. Map and compass essential.
Fog and lying snow over the mountains, possibly with falling or blowing snow, very disorientating. Map and compass essential, beware of unseen hazards such as cornices.
Precipitation Show More
Sunny winter day
Blue skies and crisp winter sunshine.
Fine, partly cloudy winter day
Dry winter day with partly cloudy skies, cloud banks covering some mountain slopes.
Banks of cloud or fog on lower or middle slopes, but higher terrain likely clear and sunny above an inversion.
Sunshine and showers
A mixed weather day, with rain on and off, briefly heavy, but mixed with periods of sunshine.
Light rain or drizzle, total amounts small, but may be persistently damp, especially where hills are shrouded in cloud.
Steady rain fairly persistent, occasionally heavy, rather wet underfoot.
Near-constant heavy rain, sometimes torrential over the mountains, very wet underfoot.
Heavy or torrential downpours with hail, risk of thunder and lightning. Seek shelter where possible.
Occasional light snow flurries, possible soft hail. Amounts little more than nuisance value, but reducing visibility for periods.
Periods of bright or sunny conditions mixed with showers or flurries of snow, sometimes hail, falling to low elevations.
Snowfall continuous or frequent, beware of conditions becoming challenging.
Continuous or almost constant heavy snowfall, large flakes falling to low elevations. Beware of near-zero visibility from falling or blowing snow, risk of blizzard conditions.
Snow and rain mix
Precipitation falling mostly as snow over higher ground, but wetter lower down with sleet or mostly rain on lowest terrain. The freezing level may vary locally and during the course of the day.
Heavy showers, snow and hail
Showery precipitation, often heavy, may merge to become constant for periods. A mix of snow and hail on higher terrain, rain or hail lower down. Risk of a rumble of thunder and isolated lightning.
Temperature Show More
Very low air temperatures or feeling bitterly cold due to wind chill on the mountains. Difficult conditions. Frostbite and hypothermia risk. Suitable protective clothing is required.
Low temperatures over the mountains all day. Suitable protective clothing required. Beware of significant wind chill at higher levels.
Feeling chilly on the hills, especially if exposed to any wind. May not feel cold when climbing, but noticeably cold when stationary. Carry suitable clothing.
Not cold, air temperature above freezing to highest summits. May feel pleasant on lower ground, but take appropriate layers. Feeling chilly if exposed to wind.
Comfortable temperatures on the hills, feeling pleasantly warm especially on lower ground. Beware of feeling cooler if exposed to wind on higher terrain.
Very warm conditions across the hills, hot on lower terrain. Beware of dehydration. Carry plenty of liquid.
Heatwave conditions. Very high temperatures on higher and lower ground. Beware of heat stroke and dehydration. Carry plenty of liquid.
Hazards Show More
Winter kit required
Extensive frozen mountain terrain with snow cover. Safe progress will require crampons and ice-axe where necessary.
Considerable lying snow over the mountains, with substantial drifting in places.
Terrain widely frozen
All ground frozen from lower elevations upward, with hard frost or snow cover. Beware of icy surfaces on lower and higher terrain. Appropriate footwear needed, crampons may be necessary.
Fast-flowing rivers and streams. Some routes may be impassable due to flooding.
Bright winter sunshine
Beware of sunburn from bright sunshine over snow covered terrain.
Very high temperatures and strong sunshine, beware of sunburn, dehydration and heat exhaustion.