Haystacks weather forecast.

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

Cloud-free timing: Around 100% early, falling to around 60% later.

A mixed day on Haystacks: summit wind broadly 10-25 mph, with gusts 20-30 mph during the evening (fresh and blowy). Thunderstorms are possible from around midday into the evening. Keep an escape route from exposed ridges and descend if thunder develops. Much calmer lower down - generally 0-10 mph in the valley, rising towards the tops. Any cloud sits well above the tops (base 700-1000 m) - clear summits. Some rain is likely, with up to around 2 mm indicated; timing and local totals remain uncertain.

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

A grey, cloudy day on Haystacks: summit wind broadly 15-30 mph, with gusts 30-40 mph during the afternoon (strong winds). A meaningful thunderstorm risk is indicated from early morning into around midday. Avoid committing to exposed ridges if storms begin to build. 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 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 18-31 mph, which changes how difficult exposed walking may feel) - the summit peak could reasonably be 18-31 mph, so treat the headline as mid-range.

Forecast confidence: Rain is possible, but forecast models differ by about 9 hours on when it arrives.

A grey, cloudy day on Haystacks: summit wind broadly 5-20 mph, with gusts 15-25 mph during the afternoon (a moderate breeze). 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. Some rain is likely, with around 2-5 mm indicated; timing and local totals remain uncertain.

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 Haystacks: summit wind broadly 15-25 mph, with gusts 25-35 mph during the evening (fresh and blowy). A meaningful thunderstorm risk is indicated from early morning into the evening. Avoid committing to exposed ridges if storms begin to build. Cloud base around 400–700 m in the morning, then around 900–1200 m around midday and 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 the morning into the afternoon. Cloud is likely to hang lowest on southern slopes; the northern 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 15-31 mph, which changes how difficult exposed walking may feel) - the summit peak could reasonably be 15-31 mph, so treat the headline as mid-range.

Forecast confidence: A low thunderstorm risk remains difficult to time precisely.

Cloud-free timing: Cloudy early, clearing later.

A wild day on Haystacks: summit wind broadly 35-50 mph, with gusts 60-70 mph during the afternoon (storm-force winds). Thunderstorms are possible from early morning into the afternoon. Keep an escape route from exposed ridges and descend if thunder develops. 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 15-25 mph in the valley, rising towards the tops. Cloud base around 400–700 m in the morning, lifting to 800–1100 m around midday and 1300–1600 m by late afternoon. Summit cloud should lift later, bringing a better chance of clear views. 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. Low confidence (Summit wind could be roughly 35-54 mph, which changes how difficult exposed walking may feel) - the summit peak could be anywhere from 35 to 54 mph; check again nearer the time.

Forecast confidence: Summit wind could be roughly 36-53 mph, which changes how difficult exposed walking may feel.

Cloud-free timing: Around 67% early, falling to around 0% later.

A rough, clagged-in day on Haystacks: summit wind broadly 30-50 mph, with gusts 55-65 mph around midday (storm-force winds). 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 10-20 mph in the valley, rising towards the tops. Cloud base around 700-1000 m in the morning, lowering to 500-800 m around midday. The top is likely to drift in and out of cloud, with the best chance of a view during the morning. 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. Cold on top: air temperature broadly 6 to 10°C, feeling around -2 to 2°C in the wind - wrap up. Confidence moderate (Summit wind could be roughly 36-53 mph, which changes how difficult exposed walking may feel) - the summit peak could reasonably be 36-53 mph, so treat the headline as mid-range.