Routes up
Pen Twyn Mawr routes: 3 ways to the top
Waun Fach CircuitHiking · 14km · from Grwyne Fawr ReservoirModerate
This route takes you over Pen Twyn Mawr as part of a circuit that also includes Waun Fach, offering expansive views of the Black Mountains.
Pen Twyn Mawr Direct AscentHiking · 8km · 500 m ascent · ~2h 25m · from Grwyne Fawr ReservoirModerate
A direct ascent to Pen Twyn Mawr from the Grwyne Fawr Reservoir, providing a straightforward hike with rewarding views.
Grwyne Fawr Reservoir to Pen Twyn MawrHiking · 10km · 600 m ascent · ~3h 0m · from Grwyne Fawr ReservoirModerate
This route starts at the Grwyne Fawr Reservoir and ascends to Pen Twyn Mawr, offering a scenic walk through the Black Mountains.
Summit today
Is it safe to climb Pen Twyn Mawr today?
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Cloud inversion · 7 days
The chance of standing above a sea of cloud on Pen Twyn Mawr each morning this week, from overnight temperature, humidity and low cloud below the 658m summit.
Dark sky · 7 days
How dark the sky gets over Pen Twyn Mawr each night this week, from cloud cover, moonlight and local light pollution.
Snow · 7 days
No snow is forecast at the summit in 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 Mawr
About Pen Twyn Mawr
Pen Twyn Mawr is 658 m (2,159 ft) high with 18 m of prominence. It is in Brecon Beacons, Wales. It is the 25th highest of the 36 summits Peakify lists in Brecon Beacons. The nearest summits are Pen y Gadair Fawr (2.4 km), Chwarel y Fan (3.1 km) and Pen Twyn Glas (3.1 km).
How high is Pen Twyn Mawr?
Pen Twyn Mawr is 658 metres high with 18 metres of prominence.
Where is Pen Twyn Mawr?
Pen Twyn Mawr is listed in Brecon Beacons, Wales.
Are there routes for Pen Twyn Mawr?
Peakify lists 3 routes for Pen Twyn Mawr, including available distance, ascent, start point, and difficulty details. The easiest is Waun Fach Circuit (14km, Moderate).
Is it safe to climb Pen Twyn Mawr 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 Mawr?
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.
