Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for the changeable conditions, with spells of rain and strong winds likely throughout. Also high for freezing levels to be largely above summits through the period. Confidence is lower in details, especially the extent of low cloud and the timing of any heavier rain or showers.
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.
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.
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.
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.
Mountain weather forecast
Windy with summit gales. Rain clearing to blustery showers and sunny spells.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
70% | 40% | 60% | 20% | 10% | 40% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
SW
41
|
SW
49
|
SW
38
|
W
39
|
W
36
|
SW
33
|
| 600m |
SW
28
|
SW
32
|
SW
27
|
W
27
|
W
22
|
SW
21
|
| 300m |
S
16
|
S
20
|
SW
17
|
W
17
|
W
13
|
SW
13
|
| Valley |
S
16
|
S
20
|
SW
16
|
W
17
|
W
14
|
SW
13
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 49 | 59 | 47 | 49 | 44 | 41 |
| 600m | 34 | 41 | 35 | 35 | 30 | 28 |
| 300m | 30 | 35 | 30 | 30 | 26 | 25 |
| Valley | 29 | 35 | 29 | 30 | 26 | 25 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
1°
|
2°
|
4°
|
2°
|
2°
|
2°
|
| 600m |
3°
|
4°
|
6°
|
5°
|
5°
|
5°
|
| 300m |
5°
|
6°
|
8°
|
7°
|
7°
|
7°
|
| Valley |
6°
|
7°
|
10°
|
9°
|
9°
|
8°
|
| Freezing Level |
1,100m
|
1,600m
|
1,400m
|
1,100m
|
1,200m
|
1,200m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-7°
|
-6°
|
-3°
|
-6°
|
-5°
|
-5°
|
| 600m |
-3°
|
-2°
|
1°
|
-1°
|
0°
|
0°
|
| 300m |
1°
|
1°
|
5°
|
3°
|
4°
|
4°
|
| Valley |
2°
|
3°
|
7°
|
5°
|
6°
|
5°
|
Additional weather information
Meteorologist's view
Winds gusting to around 50-60mph over highest summits and ridges, especially with the passage of any showers, which could include sudden unexpected gusts. Feeling cold in the wind, especially on the tops, despite the mild temperatures at lower levels. Warm waterproof layers essential.
Weather
A rather cloudy start with a band of rain moving east, followed by brighter spells and heavy showers. These could be blustery, especially with a more organised band moving through shortly after midday, with hail and a low chance of the odd rumble of thunder. Cloud thickening through the evening, with further rain likely by midnight.
Chance of cloud-free hill tops
40% at first, falling to 10% through the morning. Rising to 60% during the afternoon. Chances falling after dark to be to 20% by midnight.
Low cloud and visibility
Cloud will obscure some tops above 600m at first, but thickening and lowering to become a widespread layer at 500m as rain moves through. As this clears, many tops will see cloud-free periods, but also further spells of patchy cloud above 600m. These spells mainly associated with any further showers. Cloud returning to obscure routes above 500m after dark. Outside of cloud, visibility will be moderate to poor at first, especially in any rain, but improving to be mainly good to very good for much of the afternoon, although falling to moderate to poor again in any showers.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Overnight rain clearing to give some drier intervals to start, but staying cloudy. Further outbreaks of rain and drizzle then follow, turning heavy and persistent through the afternoon, with the best of any drier intervals in the east.
Chance of cloud-free hill tops
10%, but 30% in the north and east
Maximum wind speed expected
Southwest 35mph gusting 45-55mph
Temperature
- At 800m Plus 4 Celsius
- Valley Plus 8 Celsius rising to Plus 13 Celsius
- Freezing level Above summits
Low cloud and visibility
Low cloud will remain extensive, obscuring routes many above 600m, but some breaks possible in the north and east. Cloud descending to 400m at times in any heavier rain or drizzle, especially in the west. Visibility will be good though the drier intervals during the morning, but becoming moderate to poor in the rain.
Mountain weather information
Sun 22 Feb
Sunrise:
Sunset:
Rain at first. Brighter spells and scattered showers from late morning. Strong to gale summit winds. Freezing level above summits.
Mon 23 Feb
Sunrise:
Sunset:
Mainly dry, occasionally bright start. Rain reaching from the west from around mid-day. Strong to gale summit winds. Freezing level above summits.
Tue 24 Feb
Sunrise:
Sunset:
Rain at first, heavy with extensive hill fog, clearing for a time later in the day. Strong to gale summit winds. Freezing level above summits.
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.