Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence in a predominantly settled period. Low for chance of rain into the weekend.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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.
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
Strong and gusty winds on the hills, but staying dry.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
<05% | <05% | <05% | <05% | <05% | <05% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
E
46
|
E
35
|
E
34
|
E
32
|
E
34
|
E
40
|
| 600m |
E
25
|
E
28
|
E
28
|
E
25
|
E
21
|
E
23
|
| 300m |
E
10
|
E
17
|
E
18
|
E
17
|
SE
12
|
E
17
|
| Valley |
E
10
|
E
16
|
E
18
|
E
17
|
SE
12
|
E
16
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 54 | 44 | 44 | 41 | 42 | 50 |
| 600m | 34 | 37 | 37 | 34 | 30 | 35 |
| 300m | 23 | 28 | 29 | 29 | 24 | 31 |
| Valley | 22 | 27 | 29 | 28 | 23 | 31 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
0°
|
2°
|
5°
|
7°
|
7°
|
4°
|
| 600m |
2°
|
5°
|
8°
|
10°
|
10°
|
7°
|
| 300m |
4°
|
8°
|
11°
|
13°
|
12°
|
9°
|
| Valley |
5°
|
9°
|
13°
|
15°
|
14°
|
10°
|
| Freezing Level |
700m
|
900m
|
1,200m
|
1,400m
|
1,400m
|
1,300m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-10°
|
-6°
|
-1°
|
2°
|
1°
|
-3°
|
| 600m |
-4°
|
-2°
|
3°
|
6°
|
6°
|
2°
|
| 300m |
0°
|
4°
|
8°
|
10°
|
10°
|
6°
|
| Valley |
2°
|
6°
|
9°
|
11°
|
11°
|
7°
|
Additional weather information
Meteorologist's view
Feeling cold on the summits in the brisk winds, especially early and late in the day. Very low humidity air arriving so staying hydrated is recommended.
Weather
Clear spells during the early hours, though with patchy low cloud briefly bringing misty conditions to eastern slopes. This quickly lifting after dawn, leaving a dry day with sunny spells, the sunshine turning hazier into the afternoon as high-based cloud builds across the park.
Chance of cloud-free hill tops
70% becoming 100% by mid-morning.
Low cloud and visibility
Banks of cloud between 650m and 800m may affect east-facing slopes in the east of the National Park, this soon dispersing to leave all summits cloud free by mid-morning. Visibility will be very poor in cloud/mist but otherwise expect very good visibility, albeit with a slight haze making faraway landmarks somewhat fuzzy to see.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Patchy cloud again bringing mist to eastern slopes early in the morning, though less so than Wednesday morning. This soon clearing to allow another fine day with plentiful amounts of strong April sunshine. Clear spells holding on into the evening.
Chance of cloud-free hill tops
80% in the early hours, soon becoming 100% by mid-morning.
Maximum wind speed expected
Easterly winds on the summits of 35 mph, gusting 45 mph.
Temperature
- At 800m 2 Celsius, rising to 8 Celsius.
- Valley 5 Celsius, rising to 18 Celsius.
- Freezing level 900m first thing, rising above the summits by mid-morning.
Low cloud and visibility
Scrappy amounts of cloud at 600-800m during the early hours could bring locally poor visibility to eastern slopes. Once cleared, very good visibility for the remainder of the day.
Mountain weather information
Fri 24 Apr
Sunrise:
Sunset:
A similar day ahead with patchy cloud clearing to leave a sunny day. Lighter winds than previous days, though still a moderate to fresh southeasterly on the hills. Feeling warmer with freezing level above summits.
Sat 25 Apr
Sunrise:
Sunset:
Another fine and dry day once any valley mist and fog has cleared. Sunshine turning hazier as the day progresses with high-based cloud building. Winds continuing to ease, with just a gentle southeasterly breeze on the hills. Freezing level above the summits.
Sun 26 Apr
Sunrise:
Sunset:
A cloudier day overall, though all of this largely above the summits and still with the potential of some bright spells to break through. The small chance of patchy rain, but most of the day should be dry. Light southerly winds and freezing level above the summits by day.
Updated at:
Summit specific forecast
Mountain summit forecast map
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Key
Mountain summits
Other points of interest
Cluster of multiple stations
The Eryri (Snowdonia) mountains are made up of 90 mountain peaks including the tallest mountain in Wales, Yr Wyddfa (Snowdon), standing at 1,085 metres.