Gorllwyn weather forecast.

Cloud-free timing: Cloudy early, clearing later.

A fine day on Gorllwyn: summit wind broadly 10-25 mph, with gusts 20-30 mph during the morning (fresh and blowy). Cloud base around 500–800 m in the morning, lifting to 1400–1700 m around midday and 3000–3300 m by late afternoon. Summit cloud should lift later, bringing a better chance of clear views. Little or no rain expected.

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

Cloud-free timing: Cloudy early, clearing later.

A fine day on Gorllwyn: summit wind broadly 5-15 mph, with gusts 10-20 mph around midday (a moderate breeze). Thunderstorms are a significant hazard from the morning into the evening. Exposed summits and ridges are a poor choice while storms are nearby. Cloud base around 500–800 m in the morning, lifting to 900–1200 m around midday and 1900–2200 m by late afternoon. Summit cloud should lift later, bringing a better chance of clear views. 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.

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

Cloud-free timing: Around 0% early, improving to around 20% later.

A rough, clagged-in day on Gorllwyn: summit wind broadly 5-25 mph, with gusts 20-30 mph during the evening (fresh and blowy). Thunderstorms are forecast from early morning 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 05:00 until around 23:00. Cloud base mostly around 400–700 m through daylight. Expect clag for much of the day, though a brief clearance is possible during the evening. Cloud is likely to hang lowest on southeastern slopes; the northwestern 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.

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

Cloud-free timing: Around 0% early, improving to around 20% later.

A rough, clagged-in day on Gorllwyn: summit wind broadly 10-25 mph, with gusts 20-30 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. High spate risk based on forecast rainfall. Burns and unbridged crossings may become difficult or impassable. Most likely from around 02:00 until around 18:00. Cloud base mostly around 400–700 m through daylight. Expect clag for much of the day, though a brief clearance is possible during the evening. Cloud is likely to hang lowest on western slopes; the eastern 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. 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.

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

Cloud-free timing: Around 0% early, improving to around 60% later.

A rough, clagged-in day on Gorllwyn: summit wind broadly 10-20 mph, with gusts 20-30 mph during the evening (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 08:00 until around 20:00. Cloud base around 400–700 m through the morning, lifting to 600–900 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 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.

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

Cloud-free timing: Around 0% early, improving to around 60% later.

A mixed day on Gorllwyn: summit wind broadly 10-25 mph, with gusts 20-30 mph during the evening (fresh and blowy). 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. Cloud base around 400–700 m in the morning, lifting to 700–1000 m around midday and 900–1200 m by late afternoon. The top is likely to drift in and out of cloud, with the best chance of a view from the morning into the evening. Cloud is likely to hang lowest on southwestern slopes; the northeastern side should see somewhat higher bases and better breaks. Some rain is likely, with around 5-10 mm indicated; timing and local totals remain uncertain.

Forecast confidence: Forecast models disagree on whether meaningful rain reaches the hills during 10:00-16:00.

Cloud-free timing: Cloudy early, clearing later.

A mixed day on Gorllwyn: summit wind broadly 15-30 mph, with gusts 30-40 mph around midday (strong winds). The ground is likely to be wet after recent rain. 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 (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.