Pen y Boncyn Trefeilw weather forecast.

Cloud-free timing: Around 0% early, improving to around 100% later.

A mixed day on Pen y Boncyn Trefeilw: summit wind broadly 10-25 mph, with gusts 25-35 mph early in the morning (fresh and blowy). Cloud base around 600-900 m in the morning, lifting to 1500-1800 m around midday and 1600-1900 m by late afternoon. The top is likely to drift in and out of cloud; views may come and go. Cloud is likely to hang lowest on western slopes; the eastern side should see somewhat higher bases and better breaks. Some rain is likely, with up to around 2 mm indicated; timing and local totals remain uncertain.

Cloud-free timing: Around 75% early, improving to around 100% later.

A fine day on Pen y Boncyn Trefeilw: summit wind broadly 5-20 mph, with gusts 15-25 mph early in the morning (a moderate breeze). Any cloud sits well above the tops (base 700-1600 m) - clear summits. Little or no rain expected. Cloud base is the least certain part of this - the models are only moderately agreed, so it could sit a couple of hundred metres either way.

A fine day on Pen y Boncyn Trefeilw: summit wind broadly 5-20 mph, with gusts 20-30 mph early in the morning (fresh and blowy). Any cloud sits well above the tops (base 1500-2100 m) - clear summits. Little or no rain expected. Bright spells with UV up to 5 - sunscreen on exposed skin. Confidence moderate (ensemble members show a moderate spread) - the summit peak could reasonably be 14-20 mph, so treat the headline as mid-range. Treat the cloud base with caution - the models disagree on humidity, so it could be well above or below the figure given.

A fine day on Pen y Boncyn Trefeilw: summit wind broadly 5-15 mph, with gusts 10-20 mph during the morning (a moderate breeze). Any cloud sits well above the tops (base 1100-1800 m) - clear summits. Little or no rain expected. Bright spells with UV up to 6 - sunscreen on exposed skin. Low confidence (ensemble members are widely spread) - the summit peak could be anywhere from 5 to 11 mph; check again nearer the time. Treat the cloud base with caution - the models disagree on humidity, so it could be well above or below the figure given.

Cloud-free timing: Around 0% early, improving to around 100% later.

A fine day on Pen y Boncyn Trefeilw: summit wind broadly 0-15 mph, with gusts 15-25 mph early in the morning (a moderate breeze). Cloud base around 500-800 m in the morning, lifting to 1000-1300 m around midday and 1600-1900 m by late afternoon. The top is likely to drift in and out of cloud; views may come and go. Little or no rain expected. Bright spells with UV up to 6 - sunscreen on exposed skin. Low confidence (ensemble members are widely spread) - the summit peak could be anywhere from 6 to 14 mph; check again nearer the time.

A fine day on Pen y Boncyn Trefeilw: summit wind broadly 10-20 mph, with gusts 15-25 mph during the afternoon (fresh and blowy). Any cloud sits well above the tops (base 1500-2100 m) - clear summits. Little or no rain expected. Bright spells with UV up to 6 - sunscreen on exposed skin. Low confidence (ensemble members are widely spread) - the summit peak could be anywhere from 10 to 22 mph; check again nearer the time.

Cloud-free timing: Around 100% early, falling to around 40% later.

A fine day on Pen y Boncyn Trefeilw: summit wind broadly 10-25 mph, with gusts 20-30 mph during the evening (fresh and blowy). Little or no rain expected. Bright spells with UV up to 6 - sunscreen on exposed skin. Low confidence (ensemble members are widely spread) - the summit peak could be anywhere from 12 to 24 mph; check again nearer the time. Treat the cloud base with caution - the models disagree on humidity, so it could be well above or below the figure given.