Routes up
Pen Twyn Glas routes: 3 ways to the top
Pen Twyn Glas CircularHiking · 12km · 450 m ascent · ~3h 10m · from Grwyne Fawr ReservoirModerate
This circular route takes you through the scenic Black Mountains, offering panoramic views and a moderate challenge.
Pen Twyn Glas via Grwyne FawrHiking · 10km · 400 m ascent · ~2h 40m · from Grwyne Fawr ReservoirModerate
Starting from the reservoir, this route ascends gradually to the summit, providing a peaceful walk through remote terrain.
Pen Twyn Glas Ridge WalkHiking · 15km · 600 m ascent · ~4h 0m · from Capel-y-ffinHard
This ridge walk covers multiple peaks including Pen Twyn Glas, offering a challenging hike with rewarding views.
Summit today
Is it safe to climb Pen Twyn Glas today?
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Cloud inversion · 7 days
The chance of standing above a sea of cloud on Pen Twyn Glas each morning this week, from overnight temperature, humidity and low cloud below the 646m summit.
Dark sky · 7 days
How dark the sky gets over Pen Twyn Glas each night this week, from cloud cover, moonlight and local light pollution.
Snow · 7 days
Snowfall and lying snow at the summit over the next 7 days.
Sun today
Sunrise 07:00, sunset 16:52
9h 52m of daylight. Golden hour ends 07:49 and starts 16:02. From the summit you see the sun 06:54 to 16:57.
Nearby summits
Close to Pen Twyn Glas
About Pen Twyn Glas
Pen Twyn Glas is 646 m (2,119 ft) high with 20 m of prominence. It is in Brecon Beacons, Wales. It is the 27th highest of the 36 summits Peakify lists in Brecon Beacons. The nearest summits are Pen Allt-mawr (1.6 km), Mynydd Llysiau (2.3 km) and Pen Cerrig-calch (3.3 km).
How high is Pen Twyn Glas?
Pen Twyn Glas is 646 metres high with 20 metres of prominence.
Where is Pen Twyn Glas?
Pen Twyn Glas is listed in Brecon Beacons, Wales.
Are there routes for Pen Twyn Glas?
Peakify lists 3 routes for Pen Twyn Glas, including available distance, ascent, start point, and difficulty details. The easiest is Pen Twyn Glas Circular (12km, Moderate).
Is it safe to climb Pen Twyn Glas today?
Peakify rates each day on the summit Good, Marginal or Poor from the forecast summit wind, gusts, chance of rain and wind chill. Wind of 40 mph or gusts of 65 mph make it Poor; wind of 25 mph, gusts of 45 mph, a 60% chance of rain or a feels-like temperature of -8°C or below make it Marginal. Today's and tomorrow's ratings are at the top of this page. The rating covers the weather only: also check your route, daylight, kit and experience, and in winter whether you need an ice axe and crampons.
What weather information is shown for Pen Twyn Glas?
The page includes cached mountain forecast context, snow outlook, dark-sky signals, cloud-inversion information, sunrise, sunset, and summit planning details where available.
Peakify is run by Sam Tyler, who has climbed Yr Wyddfa 22 times. The forecast refreshes every hour; how our forecast works.
