Picws Du weather tomorrow, this weekend and 14-day summit forecast
749 m · Brecon Beacons
Picws Du is a summit on the Carmarthen Fans in the western Brecon Beacons, rising above the lake of Llyn y Fan Fach.
Picws Du today (updated 19:11, 18 Oct): up to 7°C at the summit, feeling as cold as -2°C, summit wind 24 mph gusting 30 mph, 0% chance of rain. A good day for the hills.
Picws Du weather today, tomorrow and this weekend
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Good Today Sunday 18 October
Overcast, up to 7°C at the summit, feeling as cold as -2°C, summit wind 24 mph gusting 30 mph, 0% chance of rain. Rated Good. Sunrise 07:44, sunset 18:15.
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Marginal Tomorrow Monday 19 October
Slight rain, up to 7°C at the summit, feeling as cold as -2°C, summit wind 30 mph gusting 38 mph, 98% chance of rain. Rated Marginal. Sunrise 07:46, sunset 18:13.
Best day of the next seven: Sunday 18 October, with summit gusts around 30 mph and a 0% chance of rain. Peakify picks it as the day with the lightest gusts, after a penalty for any chance of rain over 40%.
Picws Du 14-day summit weather forecast
Every day the cache holds from today, at summit height. Temperatures in °C, wind and gusts in mph, rain as the day's highest chance. Days 8 to 14 are marked less certain: forecasts lose skill quickly beyond a week, so read them as a trend.
| Day | Verdict | Weather | High / low | Feels like | Wind / gust | Rain | Snow |
|---|---|---|---|---|---|---|---|
| Today | Good | Overcast | 7° / 2° | -2° | 24 / 30 mph | 0% | — |
| Tomorrow | Marginal | Slight rain | 7° / 3° | -2° | 30 / 38 mph | 98% | — |
| Tue 20 Oct | Marginal | Light drizzle | 8° / 1° | -2° | 23 / 29 mph | 79% | — |
| Wed 21 Oct | Poor | Slight rain | 6° / 0° | -4° | 46 / 57 mph | 75% | — |
| Thu 22 Oct | Marginal | Dense drizzle | 7° / 2° | -1° | 32 / 40 mph | 88% | — |
| Fri 23 Oct | Poor | Slight rain | 4° / 1° | -7° | 57 / 71 mph | 96% | — |
| Sat 24 Oct | Poor | Dense drizzle | 9° / 1° | -3° | 43 / 53 mph | 69% | — |
| Days 8 to 14: less certain | |||||||
| Sun 25 Oct | Poor (less certain) | Light drizzle | 10° / 3° | -2° | 43 / 54 mph | 75% | — |
| Mon 26 Oct | Poor (less certain) | Slight rain showers | 11° / 3° | -3° | 55+ / 75+ mph | 70% | — |
| Tue 27 Oct | Poor (less certain) | Slight rain showers | 11° / 3° | -2° | 55+ / 75+ mph | 73% | — |
| Wed 28 Oct | Marginal (less certain) | Light drizzle | 7° / 2° | -2° | 37 / 46 mph | 51% | — |
| Thu 29 Oct | Poor (less certain) | Slight rain showers | 8° / 4° | 1° | 52 / 65 mph | 39% | — |
| Fri 30 Oct | Poor (less certain) | Thunderstorm | 11° / 5° | 3° | 55 / 69 mph | 39% | — |
| Sat 31 Oct | Marginal (less certain) | Moderate drizzle | 8° / 1° | -1° | 34 / 43 mph | 45% | — |
The cached forecast has no freezing level; snow is the model's summit snowfall for the day.
How the Picws Du summit forecast is made
The numbers come from the Open-Meteo weather model for the summit's position at 749 m, in the mountain's local time. A valley forecast would understate the summit badly, so the wind is worked out at summit height from the model's upper-air winds: the standard 10 m wind sits over the model's smoothed ground and is roughly half what an exposed top gets.
Peakify rates each day 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. The verdict is the same one shown on the main peak page and in the Peakify app.
"Feels like" is the coldest apparent temperature of the day, which combines air temperature, wind and humidity. On a windy summit it can be well below the air temperature, so pack for that figure, not the high.
For a second opinion before a big day, read the Met Office mountain forecast or MWIS for the area. They are written by forecasters and cover hazards such as cloud on the tops and visibility that a model table can't.
Questions about Picws Du
What is the Picws Du weather tomorrow?
Monday 19 October: slight rain, up to 7°C at the summit, feeling as cold as -2°C, summit wind 30 mph gusting 38 mph, 98% chance of rain. Rated Marginal.
What is the Picws Du weather this weekend?
Sunday 18 October: overcast, up to 7°C at the summit, feeling as cold as -2°C, summit wind 24 mph gusting 30 mph, 0% chance of rain. Rated Good.
Is there a 14-day Picws Du weather forecast?
Yes. This page lists up to 14 days of summit weather for Picws Du, each with a Good, Marginal or Poor verdict. Days 8 to 14 are less certain: use them to spot a settled or stormy spell, not to plan a day.
Where does the Picws Du summit forecast come from?
From the Open-Meteo weather model for the summit's position at 749 m, refreshed every few hours. Wind is worked out at summit height from the model's upper-air winds, because the standard 10 m wind is roughly half what a summit gets.