Routes up
Y Llethr routes: 3 ways to the top
Cwm Nantcol western approachHiking · 4.8 km one way · 580 m ascent · ~1h 55m · from Cil-cychwyn public pathHard
Graigddu-isaf via Rhinog FachHiking · 6.6 km one way · 660 m ascent · ~2h 25m · from Cwrt Forest / Graigddu-isaf car parkHard
Cwm Mynach via Diffwys and Crib-y-rhiwHiking · 7.0 km one way · 720 m ascent · ~2h 35m · from Cwm Mynach public forest pathHard
Summit today
Is it safe to climb Y Llethr today?
Y Llethr today (updated 12:21, 27 Oct): up to 8°C at the summit, feeling as cold as 1°C, summit wind 47 mph gusting 59 mph, 100% chance of rain. A poor day for the hills. Best day this week: Saturday, summit gusts 7 mph.
Y Llethr weather today
Moderate drizzle, up to 8°C at the summit, feeling as cold as 1°C, summit wind 47 mph gusting 59 mph, 100% chance of rain. Rated Poor.
Y Llethr weather tomorrow
Thursday 29 October: overcast, up to 10°C at the summit, feeling as cold as 3°C, summit wind 29 mph gusting 37 mph, 27% chance of rain. Rated Marginal.
Y Llethr weather this weekend
Saturday 31 October: fog, up to 11°C at the summit, feeling as cold as -2°C, summit wind 6 mph gusting 7 mph, 4% chance of rain. Rated Good.
Sunday 1 November: fog, up to 6°C at the summit, feeling as cold as -2°C, summit wind 22 mph gusting 27 mph, 2% chance of rain. Rated Good.
Y Llethr summit forecast, next 7 days
| Day | Verdict | High/low | Feels like | Wind/gust mph | Rain or snow |
|---|
| TodayModerate drizzle | Poor | 8°/6° | 1° | 47/59 | 100% |
|---|
| TomorrowOvercast | Marginal | 10°/5° | 3° | 29/37 | 27% |
|---|
| Fri 30Fog | Marginal | 10°/1° | -1° | 30/38 | 8% |
|---|
| Sat 31Fog | Good | 11°/1° | -2° | 6/7 | 4% |
|---|
| Sun 1Fog | Good | 6°/0° | -2° | 22/27 | 2% |
|---|
| Mon 2Overcast | Good | 7°/1° | -2° | 23/28 | 0% |
|---|
| Tue 3Fog | Good | 6°/-1° | -4° | 11/17 | 0% |
|---|
Y Llethr 14-day weather forecast: days 8 to 13, less certain
| Day | Verdict | High/low | Feels like | Wind/gust mph | Rain or snow |
|---|
| Wed 4Fog | Good | 6°/-4° | -6° | 13/16 | 2% |
|---|
| Thu 5Fog | Good | 6°/-1° | -4° | 14/23 | 4% |
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| Fri 6Mainly clear | Good | 4°/-4° | -7° | 17/21 | 6% |
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| Sat 7Overcast | Good | 5°/-2° | -6° | 22/28 | 18% |
|---|
| Sun 8Fog | Good | 3°/-3° | -6° | 24/31 | 23% |
|---|
| Mon 9Fog | Marginal | 4°/-6° | -10° | 23/29 | 31% |
|---|
Cloud inversion · 7 days
The chance of standing above a sea of cloud on Y Llethr each morning this week, from overnight temperature, humidity and low cloud below the 756m summit.
Dark sky · 7 days
How dark the sky gets over Y Llethr 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 07:05, sunset 16:53
9h 48m of daylight. Golden hour ends 07:56 and starts 16:02. From the summit you see the sun 06:59 to 16:58.
Nearby summits
Close to Y Llethr
About Y Llethr
Y Llethr is the highest of the Rhinogydd, the hills between Harlech and the Mawddach. Rhinog Fach lies 1.3 km north, Crib-y-rhiw 0.9 km south and Diffwys 2.4 km south along the main ridge. A drystone wall runs along much of the crest, and Llyn Hywel sits in the hollow below Y Llethr and Rhinog Fach.
The usual approach starts in Cwm Nantcol and climbs to Bwlch Drws Ardudwy, the pass between Rhinog Fawr and Rhinog Fach. From there you climb rough ground past Llyn Hywel or over Rhinog Fach to the summit. The northern Rhinogydd are known for deep heather and boulders, so expect slow progress off the paths.
Y Llethr's own top is grassy, a change from its rocky neighbours. It is a Hewitt, a Nuttall and a Marilyn.
Y Llethr is 756 m (2,480 ft) high with 561 m of prominence. It is in Snowdonia, Wales. It is the 48th highest of the 152 summits Peakify lists in Snowdonia. The nearest summits are Crib-y-rhiw (0.9 km), Rhinog Fach (1.3 km) and Diffwys (2.4 km).
What is the highest of the Rhinogydd?
Y Llethr, at 756 m, is the highest of the Rhinog hills.
Can you climb Y Llethr and Rhinog Fach together?
Yes. Rhinog Fach is 1.3 km north, and the walk from Cwm Nantcol often takes in both.
How hard is Y Llethr?
The summit is grassy, but the approaches cross heather, boulders and steep ground. Allow more time than the distance suggests.
How high is Y Llethr?
Y Llethr is 756 metres high with 561 metres of prominence.
Where is Y Llethr?
Y Llethr is listed in Snowdonia, Wales.
Are there routes for Y Llethr?
Peakify lists 3 routes for Y Llethr, including available distance, ascent, start point, and difficulty details. The easiest is Cwm Nantcol western approach (4.8 km one way, Hard).
Is it safe to climb Y Llethr 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 is the weather on Y Llethr tomorrow?
Thursday 29 October: overcast, up to 10°C at the summit, feeling as cold as 3°C, summit wind 29 mph gusting 37 mph, 27% chance of rain. Rated Marginal.
What is the weather on Y Llethr this weekend?
Saturday 31 October: fog, up to 11°C at the summit, feeling as cold as -2°C, summit wind 6 mph gusting 7 mph, 4% chance of rain. Rated Good. Sunday 1 November: fog, up to 6°C at the summit, feeling as cold as -2°C, summit wind 22 mph gusting 27 mph, 2% chance of rain. Rated Good.
What weather information is shown for Y Llethr?
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.
