Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for unsettled weather, lower confidence in the timing and rainfall accumulations on Tuesday night.
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.
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.
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.
Mountain weather forecast
Mostly fine and dry. Wind and rain arriving from the west during the evening.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
<05% | <05% | <05% | 10% | 80% | 90% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
S
15
|
SW
20
|
SW
23
|
S
29
|
S
36
|
SE
39
|
| 600m |
S
14
|
S
17
|
S
21
|
S
25
|
S
27
|
SE
29
|
| 300m |
S
8
|
S
12
|
S
15
|
S
17
|
S
18
|
SE
21
|
| Valley |
S
9
|
S
12
|
S
15
|
S
17
|
S
19
|
SE
22
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 18 | 25 | 30 | 37 | 45 | 48 |
| 600m | 17 | 22 | 28 | 33 | 36 | 39 |
| 300m | 14 | 19 | 24 | 29 | 31 | 36 |
| Valley | 15 | 19 | 24 | 29 | 31 | 36 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
3°
|
3°
|
4°
|
5°
|
5°
|
4°
|
| 600m |
5°
|
6°
|
7°
|
8°
|
7°
|
6°
|
| 300m |
7°
|
8°
|
10°
|
11°
|
10°
|
9°
|
| Valley |
8°
|
10°
|
11°
|
12°
|
11°
|
10°
|
| Freezing Level |
1,200m
|
1,200m
|
1,300m
|
1,400m
|
1,500m
|
1,800m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-2°
|
-3°
|
-2°
|
-1°
|
-2°
|
-3°
|
| 600m |
1°
|
1°
|
2°
|
3°
|
2°
|
1°
|
| 300m |
5°
|
6°
|
7°
|
8°
|
6°
|
5°
|
| Valley |
6°
|
8°
|
8°
|
9°
|
8°
|
6°
|
Additional weather information
Meteorologist's view
While the valleys may feel pleasant in the sunshine, there remains a risk of severe chill on the summits. It is advisable to wear layers as well as ensuring adequate sun protection.
Weather
A largely fine day with plenty of sunny spells across the park, patchy low cloud may graze western slopes, especially during the morning, clearing and lifting above summits by the afternoon. A band of moderate, occasionally heavy rain arriving from the west in the evening. Moderate winds increasing into the afternoon.
Chance of cloud-free hill tops
70% at first, becoming 90% by the afternoon, falling to 40% in the evening.
Low cloud and visibility
Poor visibilities on western slopes at first in association with cloud covering hill tops above 300-400m, this gradually lifts above summits by the afternoon with visibilities becoming very good to excellent. As the rain arrives from the west, cloud fills in and cloud bases lower, obscuring hills above 300-400m.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A band of moderate, occasionally heavy rain clears east during the early hours of Wednesday morning. This is followed by further cloudy conditions with outbreaks of light rain and drizzle during Wednesday morning. By the afternoon, it will become largely dry with some occasional breaks in the cloud to see the odd spot of sunshine.
Chance of cloud-free hill tops
20% becoming 70% by the end of the day.
Maximum wind speed expected
Southwesterly 20mph becoming easterly 15mph with gusts up to 25mph.
Temperature
- At 800m Plus 03 Celsius becoming Plus 05 Celsius.
- Valley Plus 09 Celsius becoming Plus 15 Celsius.
- Freezing level Above summits.
Low cloud and visibility
Low cloud covering hills above 300m during the morning with outbreaks of rain and drizzle, reducing the visibility to poor or very poor. By the afternoon, cloud bases begin to lift to 700-800m and becoming dry with visibilities improving to good or very good.
Mountain weather information
Thu 24 Apr
Sunrise:
Sunset:
Dry and bright with sunny spells. Freezing level above summits. Moderate south-southeasterly winds.
Fri 25 Apr
Sunrise:
Sunset:
Hazy sunshine ahead of rain arriving in the evening. Freezing level above summits. Fresh southerly winds.
Sat 26 Apr
Sunrise:
Sunset:
Cloudy with outbreaks of rain, perhaps some bright spells in the afternoon. Freezing level above summits. Fresh to strong south-southwesterly winds.
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.