Cyfrwy weather forecast.

Cloud-free timing: Cloudy early, clearing later.

A wild day on Cyfrwy: summit wind broadly 20-40 mph, with gusts 45-55 mph during the morning (gale-force winds). Much calmer lower down - generally 5-15 mph in the valley, rising towards the tops. Cloud base around 500–800 m in the morning, lifting to 1400–1700 m around midday and 1800–2100 m by late afternoon. Summit cloud should lift later, bringing a better chance of clear views. Little or no rain expected. Confidence moderate (forecast models agree on the walking impact of the wind) - the summit peak could reasonably be 33-36 mph, so treat the headline as mid-range.

Forecast confidence: Thunderstorm timing is inherently uncertain and may shift by several hours.

Cloud-free timing: Around 0% early, improving to around 40% later.

A grey, cloudy day on Cyfrwy: summit wind broadly 10-30 mph, with gusts 30-40 mph early in the morning (strong winds). Thunderstorms are a significant hazard from the morning into the evening. Exposed summits and ridges are a poor choice while storms are nearby. There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. Most likely from around 04:00 until around 20:00. Much calmer lower down - generally 0-10 mph in the valley, rising towards the tops. Cloud base around 500–800 m through the morning, lifting to 700–1000 m by late afternoon. Expect clag for much of the day, though a brief clearance is possible during the evening. Some rain is likely, with up to around 2 mm indicated; timing and local totals remain uncertain. Confidence moderate (forecast models agree on the walking impact of the wind) - the summit peak could reasonably be 21-28 mph, so treat the headline as mid-range.

Forecast confidence: Thunderstorm timing is inherently uncertain and may shift by several hours.

A rough, clagged-in day on Cyfrwy: summit wind broadly 15-35 mph, with gusts 35-45 mph during the morning (strong winds). Thunderstorms are forecast from late afternoon into the evening. Avoid exposed summits and ridges during the risk period. There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. Most likely from around 08:00 until around 03:00 the following day. Much calmer lower down - generally 5-15 mph in the valley, rising towards the tops. Cloud base mostly around 400–700 m through daylight. Expect the top to stay in cloud for most or all of daylight, with no dependable break. A persistently wet day is possible, with around 10-20 mm indicated; local totals could vary considerably. Confidence moderate (forecast models agree on the walking impact of the wind) - the summit peak could reasonably be 22-33 mph, so treat the headline as mid-range.

Forecast confidence: Thunderstorm timing is inherently uncertain and may shift by several hours.

A rough, clagged-in day on Cyfrwy: summit wind broadly 15-25 mph, with gusts 25-35 mph during the afternoon (fresh and blowy). A meaningful thunderstorm risk is indicated from the morning into the evening. Avoid committing to exposed ridges if storms begin to build. The ground is likely to be wet after recent rain. There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. Most likely from around 00:00 until around 03:00 the following day. Cloud base around 400–700 m through the morning, lifting to 700–1000 m by late afternoon. Expect the top to stay in cloud for most or all of daylight, with no dependable break. Cloud is likely to hang lowest on northwestern slopes; the southeastern side should see somewhat higher bases and better breaks. A persistently wet day is possible, with around 5-10 mm indicated; local totals could vary considerably.

Forecast confidence: Thunderstorm timing is inherently uncertain and may shift by several hours.

A rough, clagged-in day on Cyfrwy: summit wind broadly 10-25 mph, with gusts 25-35 mph early in the morning (fresh and blowy). A meaningful thunderstorm risk is indicated from around midday into the evening. Avoid committing to exposed ridges if storms begin to build. The ground is likely to be wet after recent rain. There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. Most likely from around 00:00 until around 23:00. Much calmer lower down - generally 0-10 mph in the valley, rising towards the tops. Cloud base mostly around 400–700 m through daylight. Expect the top to stay in cloud for most or all of daylight, with no dependable break. Cloud is likely to hang lowest on southern slopes; the northern side should see somewhat higher bases and better breaks. A persistently wet day is possible, with around 10-20 mm indicated; local totals could vary considerably. Confidence moderate (Summit wind could be roughly 16-31 mph, which changes how difficult exposed walking may feel) - the summit peak could reasonably be 16-31 mph, so treat the headline as mid-range.

Forecast confidence: Thunderstorm timing is inherently uncertain and may shift by several hours.

A rough, clagged-in day on Cyfrwy: summit wind broadly 20-40 mph, with gusts 40-50 mph during the evening (gale-force winds). Thunderstorms are a significant hazard from early morning into the evening. Exposed summits and ridges are a poor choice while storms are nearby. The ground is likely to be wet after recent rain. There could be a spate risk based on forecast rainfall. Burns and unbridged crossings may rise quickly. Most likely from around 08:00 until around 03:00 the following day. Much calmer lower down - generally 5-15 mph in the valley, rising towards the tops. Cloud base mostly around 400–700 m through daylight. Expect the top to stay in cloud for most or all of daylight, with no dependable break. Cloud is likely to hang lowest on southwestern slopes; the northeastern side should see somewhat higher bases and better breaks. A persistently wet day is possible, with around 5-10 mm indicated; local totals could vary considerably. Confidence moderate (Summit wind could be roughly 25-40 mph, which changes how difficult exposed walking may feel) - the summit peak could reasonably be 25-40 mph, so treat the headline as mid-range.

Forecast confidence: Thunderstorm timing is inherently uncertain and may shift by several hours.

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

A grey, cloudy day on Cyfrwy: summit wind broadly 20-35 mph, with gusts 40-50 mph during the afternoon (gale-force winds). A meaningful thunderstorm risk is indicated from early morning into the evening. Avoid committing to exposed ridges if storms begin to build. The ground is likely to be wet after recent rain. Much calmer lower down - generally 5-15 mph in the valley, rising towards the tops. Cloud base around 400–700 m through the morning, lifting to 1900–2200 m by late afternoon. The top is likely to drift in and out of cloud, with the best chance of a view from late afternoon into the evening. 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 around 2-5 mm indicated; timing and local totals remain uncertain. Confidence moderate (Summit wind could be roughly 22-39 mph, which changes how difficult exposed walking may feel) - the summit peak could reasonably be 22-39 mph, so treat the headline as mid-range.