Mountain weather
Snowdonia Mountain weather forecast table
Confidence
High for dry and settled conditions today, moderate for the extent of any rain overnight tonight and at first Wednesday.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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.
Thunderstorms
Lightning is a significant mountain hazard which can result in serious injury or death. Mountain terrain often leaves one highly exposed to lightning strikes. Hail may give unpleasant conditions with torrential rain and localised flash flooding also possible, mainly in Summer months.
Mountain weather forecast
A predominantly dry day with light winds and good visibility.
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
10% | <05% | <05% | <05% | <05% | 20% |
Wind direction and speed (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
SW
20
|
SW
16
|
SW
12
|
SW
9
|
SW
6
|
S
4
|
| 600m |
S
17
|
SW
15
|
SW
11
|
SW
8
|
SW
5
|
S
3
|
| 300m |
S
11
|
SW
10
|
SW
6
|
SW
4
|
SW
3
|
S
2
|
| Valley |
S
11
|
SW
10
|
SW
6
|
SW
4
|
W
3
|
SE
2
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m | 24 | 20 | 17 | 13 | 8 | 6 |
| 600m | 21 | 20 | 18 | 13 | 7 | 5 |
| 300m | 18 | 16 | 15 | 11 | 6 | 5 |
| Valley | 18 | 16 | 15 | 11 | 6 | 5 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
6°
|
7°
|
8°
|
9°
|
9°
|
9°
|
| 600m |
8°
|
9°
|
10°
|
11°
|
11°
|
10°
|
| 300m |
11°
|
12°
|
13°
|
14°
|
14°
|
12°
|
| Valley |
12°
|
13°
|
15°
|
15°
|
15°
|
13°
|
| Freezing Level |
1,700m
|
1,800m
|
1,900m
|
2,000m
|
2,100m
|
2,100m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
1°
|
2°
|
5°
|
7°
|
7°
|
8°
|
| 600m |
4°
|
5°
|
8°
|
9°
|
10°
|
10°
|
| 300m |
8°
|
10°
|
12°
|
13°
|
14°
|
12°
|
| Valley |
10°
|
11°
|
14°
|
15°
|
15°
|
13°
|
Additional weather information
Weather
Cloudy at first with a low chance for some patchy light rain or drizzle. Low cloud lifting this morning with some bright or sunny intervals by afternoon. Cloud increasing again this evening with some light and patchy rain developing.
Chance of cloud-free mountain/hill tops at 800m
30% with broken cloud above 500 m at first, increasing to 80% with cloud above most summits by afternoon.
Ground conditions
No recent ground conditions report available. For archived reports see - http://www.snowdonia.gov.wales/visiting/walking/ground-conditions
Visibility
Good or very good outside of cloud, with distant peaks clearly visible through much of the day. Visibility will be reduced in any rain or drizzle with distant peaks obscured but nearby peaks remaining visible.
Meteorologist's view
UV levels could become high in any spells of afternoon sunshine.
Mountain weather information
Weather
Cloudy with outbreaks of rain, occasionally heavy, through the early hours. Cloud and rain will soon clear in the morning with sunny spells by afternoon, and perhaps the odd shower towards evening.
Chance of cloud-free mountain/hill tops at 800m
10-30% with broken cloud above 300 m, increasing to 80% with scattered cloud above 600 m by afternoon.
Maximum wind speed expected
NE 10-15mph becoming SW 15-20 gust 25mph by evening.
Temperature
- At 800m Plus 06 Celsius increasing to Plus 08 Celsius.
- Valley Plus 10 Celsius increasing to Plus 15 Celsius.
- Freezing level Above summit
Visibility
Distant peaks obscured at first but nearby peaks and ridges visible in rain. However, even nearby ridges and summits obscured in cloud. Visibility improving generally good or very good by the afternoon with distant peaks clearly visible.
Mountain weather information
Thursday 20 June
Sunrise:
Sunset:
Sunny spells and occasional showers. Fresh occasionally strong west to southwest winds on the summits. High UV levels during the afternoon.
Friday 21 June
Sunrise:
Sunset:
Mainly dry with sunny spells. Moderate westerly winds on the hills. High UV levels during the afternoon.
Saturday 22 June
Sunrise:
Sunset:
Dry with hazy sunshine. Light to moderate southeast winds. High UV levels during the afternoon.
Updated at:
Summit specific forecast map
Summit specific forecasts for SnowdoniaThe 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.