Mountain weather
Snowdonia Mountain weather forecast table
Confidence
High for mainly fair weather this weekend and on Monday, though low confidence for extent of fog at low levels and lower confidence for details after Monday.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Strong sunlight
Harmful UV levels from sunlight increase with altitude giving a greater risk of sunburn and eye damage, even on some overcast days. On breezy days, the cooling effect of wind on exposed skin may disguise any feeling of sunburn until it is too late. If there is snow cover, glare increases the effect of UV rays especially on the eyes. It is advisable to wear sun block, protective clothing such as a long-sleeved top and hat and have good quality eye protection.
Gales
Gale force winds (gusts over 50mph) make walking difficult and strenuous with a potential to be blown over by gusts. There is often a marked increase in winds through cols or on exposed ridges and summits. Distances can take longer to cover and compass bearings become harder to follow accurately.
Severe chill effect
Wind significantly lowers the ‘feels-like’ temperature relative to the actual temperature, with even moderate winds significantly adding to the chilling effect. Strong winds can result in a severe and debilitating wind chill many degrees below the actual temperature. This effect will be enhanced in rain or wet snow. Without protection, prolonged exposure could result in frost nip or frostbite on exposed parts of the body and/or hypothermia.
Poor visibility
Poor visibility presents challenging route finding conditions. Visibility could be significantly less than 50 metres in all directions with few or no visual references, especially on featureless moors or plateaux. Distances become hard to judge and cliff or cornice edges can be difficult to recognise. These conditions require good navigational skills. There is a risk of white-out conditions when mist or fog is combined with extensive snow cover.
Mountain weather forecast
Rather cold, mainly dry but cloudier this afternoon. Frost quickly developing later.
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
10% | 10% | 20% | 10% | <05% | <05% |
Wind direction and speed (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
NW
19
|
W
14
|
NW
14
|
NW
15
|
NW
19
|
NW
17
|
| 600m |
NW
10
|
W
7
|
NW
10
|
NW
10
|
NW
10
|
N
8
|
| 300m |
NW
3
|
SW
2
|
NW
4
|
NW
4
|
NW
4
|
NW
3
|
| Valley |
NW
4
|
SW
3
|
NW
5
|
NW
5
|
NW
4
|
NW
3
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m | 23 | 16 | 18 | 18 | 23 | 20 |
| 600m | 13 | 9 | 12 | 13 | 13 | 11 |
| 300m | 10 | 5 | 10 | 10 | 10 | 7 |
| Valley | 10 | 5 | 11 | 11 | 11 | 8 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
-2°
|
-2°
|
-1°
|
-1°
|
-1°
|
-1°
|
| 600m |
0°
|
0°
|
1°
|
1°
|
1°
|
1°
|
| 300m |
2°
|
2°
|
4°
|
4°
|
3°
|
2°
|
| Valley |
3°
|
3°
|
5°
|
6°
|
4°
|
3°
|
| Freezing Level |
500m
|
500m
|
600m
|
600m
|
700m
|
700m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
-9°
|
-8°
|
-7°
|
-7°
|
-8°
|
-8°
|
| 600m |
-4°
|
-3°
|
-3°
|
-3°
|
-3°
|
-3°
|
| 300m |
0°
|
0°
|
2°
|
2°
|
1°
|
1°
|
| Valley |
1°
|
1°
|
3°
|
4°
|
2°
|
2°
|
Additional weather information
Weather
Mostly dry and sunny this morning, but with patchy cloud at times bringing the chance of the odd shower across northern areas of Snowdonia, with snow down to 500m. Cloudier this afternoon with a good deal of high cloud spreading over the Park, but any showers will die away. High cloud breaking up this evening, then dry with clear periods and a sharp frost quickly developing.
Chance of cloud-free mountain/hill tops at 800m
80-90% with generally well scattered cloud over the tops, but 50 or 60% in from mid-morning over northern ranges with occasionally broken cloud down to 500m.
Ground conditions
Area - Snowdon Date - 17 January 2020 Time - 13.00pm Snow Above - 650metres Report By - Snowdon warden Route Taken PYG track Conditions Depth of snow increases with altitude. Paths difficult to follow. Steep bank of snow at top of path. Sections of ice on paths. Essential Kit The following is a list of additional kit required based on the current conditions. Standard winter kit required. Ice axe and crampons essential. Additional Information It gets dark at 16.30 .
Visibility
Very good, but some reductions in showers.
Meteorologist's view
Rather cold, with some chill effect at height and the odd snow shower too. The wind will generally ease. Mostly dry today with good views over the hills, but some glare from lying snow.
Mountain weather information
Weather
Largely clear and frosty overnight, but some fog developing in valleys. Then a dry, mostly fine and sunny day though any fog patches will be slow to clear and high cloud will likely spread in from the northwest through the afternoon.
Chance of cloud-free mountain/hill tops at 800m
90% or more with any cloud generally well above the tops
Maximum wind speed expected
Northwest 10mph, becoming west or southwesterly 15-20mph later
Temperature
- At 800m Minus 3 to minus 5 C
- Valley Minus 5 C rising to plus 3 C during the afternoon
- Freezing level Falling to 500m, but rising to 700m again later
Visibility
Very good, but very poor in fog at low levels.
Mountain weather information
Monday 20 January
Sunrise:
Sunset:
Mostly dry and bright, but hazy with fog in some valleys and a good deal of high cloud. Cloud perhaps thickening later in the day to bring patchy drizzle to western slopes. Moderate or fresh southwesterly winds. Freezing level 700m, temporarily rising close to the summits during the day.
Tuesday 21 January
Sunrise:
Sunset:
Cloudier, with murky conditions and extensive mist and hill fog. Also patchy light rain or drizzle developing, especially on western slopes, falling as sleet or snow at height. Moderate westerly winds, freezing level rising close to or just above the summits.
Wednesday 22 January
Sunrise:
Sunset:
Mostly cloudy with mist at lower levels and low cloud and patchy rain or drizzle, especially over western slopes, but some brighter spells may develop in the afternoon, although mainly across eastern areas Light northwest winds and freezing level close to or just above the tops.
Updated at:
Summit specific forecast
Mountain summit forecast map
Key
Mountain summits
Other points of interest
Cluster of multiple stations
The Snowdonia mountains are made up of 90 mountain peaks including the tallest mountain in Wales, Snowdon, standing at 1,085 metres.
The region can be divided into four areas with the northernmost area the most popular, including peaks such as Moel Hebog, Mynydd Mawr and the Nantlle Ridge. Many hikers tend to concentrate on Snowdon itself regarding it as a fine mountain. However it can become quite crowded, with the peak welcoming around half a million visitors every year, of which four fifths scale the peak on foot, while the remainder choose to take the train instead.
One of Snowdon’s main attractions is the sheer number and variety of paths that reach the peak. This means that everyone from mountaineering novices to climbing experts should find a way up the mountain that will suit their abilities or provide them with a sufficient test. The easiest is the Llanberis path which, being the longest, has the most shallow ascent. In contrast, the Watkin Path is widely seen as being the most demanding ascent, despite also being considered the prettiest.