Mountain weather
Snowdonia Mountain weather forecast table
Confidence
High confidence for wet weather. Moderate confidence in strength of wind gusts Sunday. Low confidence for Tuesday's and Wednesday's forecast.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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.
Heavy persistent rain
Heavy and persistent rain can lead to drenched clothing and footwear with waterproofs often becoming soaked through, especially if accompanied by strong winds. This can lead to significant loss of body heat and an increased likelihood of hypothermia. Terrain may turn increasingly boggy underfoot while streams can flood and become impassable. There may also be a risk of flooding in valleys or glens. If there is snow cover, a heightened avalanche hazard is possible and avalanche reports should be consulted where available.
Storm force winds
Storm force winds (gusts over 70mph) make walking very strenuous with any mobility virtually impossible over exposed ground. Where these conditions occur there is a high risk of being blown over and even standing may be impossible at times with a risk of being blown off one’s feet. Basic tasks such as using a map, eating, putting on extra clothing or communication become extremely difficult away from any shelter.
Mountain weather forecast
Persistent rain and hill fog.
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
>95% | >95% | >95% | >95% | >95% | >95% |
Wind direction and speed (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
SW
30
|
SW
28
|
SW
25
|
SW
24
|
SW
30
|
SW
41
|
| 600m |
SW
21
|
SW
21
|
SW
20
|
SW
19
|
SW
21
|
SW
28
|
| 300m |
SW
13
|
SW
14
|
SW
13
|
SW
13
|
SW
14
|
SW
19
|
| Valley |
SW
13
|
SW
14
|
SW
13
|
SW
13
|
SW
14
|
SW
19
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m | 35 | 34 | 33 | 31 | 38 | 52 |
| 600m | 25 | 26 | 27 | 25 | 29 | 39 |
| 300m | 22 | 22 | 22 | 21 | 24 | 35 |
| Valley | 22 | 23 | 22 | 21 | 24 | 34 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
11°
|
10°
|
10°
|
10°
|
11°
|
10°
|
| 600m |
12°
|
12°
|
12°
|
12°
|
12°
|
12°
|
| 300m |
13°
|
13°
|
14°
|
14°
|
14°
|
13°
|
| Valley |
14°
|
14°
|
15°
|
15°
|
15°
|
14°
|
| Freezing Level |
3,600m
|
3,700m
|
3,600m
|
3,500m
|
3,500m
|
3,900m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
6°
|
6°
|
6°
|
7°
|
6°
|
5°
|
| 600m |
8°
|
8°
|
8°
|
9°
|
9°
|
7°
|
| 300m |
11°
|
11°
|
11°
|
12°
|
11°
|
10°
|
| Valley |
12°
|
12°
|
12°
|
13°
|
13°
|
11°
|
Additional weather information
Meteorologist's view
Wind gusts quickly strengthening after 1800 to gale or severe gales force strength over ridges and summits, and also above 600 m after 2200. Low risk of storm force winds developing over ridges and summits by midnight.
Weather
Persistent mostly light rain all day, occasionally turning to drizzle across eastern areas this afternoon. Some heavy rain is possible at times, this morning and especially this evening, across western areas. Persistent low cloud will give fog above 450m.
Chance of cloud-free mountain/hill tops at 800m
0%, cloud bases at 450m through today.
Visibility
4000m in rain, 2000m in drizzle and less than 100m in fog.
Ground conditions
Please see - https://www.eryri.llyw.cymru/visiting/walking/ground-conditions
Mountain weather information
Weather
Severe gales at first on Sunday, with storm force winds likely over the highest ridges and peaks. The wind gradually eases a little through the day, but still gales persist and there will be a noticeable wind-chill. Rain, low cloud and hill fog overnight will clear in the early hours of Sunday morning leaving sunny spells and scattered showers.
Chance of cloud-free mountain/hill tops at 800m
0% until 0500 with cloud bases around 450m. Thereafter cloud lifting and clearing to give 100% chance.
Maximum wind speed expected
Southwesterly winds gusting 60-70 mph
Temperature
- At 800m Plus 11 Celsius decreasing 6 Celsius
- Valley Plus 9 Celsius, becoming plus 16 Celsius.
- Freezing level Well above tops
Visibility
Very poor at first under low cloud, becoming excellent after 0500.
Mountain weather information
Monday 6 July
Sunrise:
Sunset:
Sunny spells and isolated mainly light showers, becoming largely dry. Windy at first, with gales above 600m. There will be a significant windchill for July, even though the wind gradually eases.
Tuesday 7 July
Sunrise:
Sunset:
Most likely dry, clear at first then sunny spells, but low cloud and drizzle may arrive later in the day.
Wednesday 8 July
Sunrise:
Sunset:
Most likely dry with clear or sunny spells and light winds, but there is a chance of increasing cloud later in the day and outbreaks of rain developing.
Updated at:
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.