Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High
This evening forecast
Any remaining showers generally clearing though the evening to leave clearer conditions with winds easing somewhat.
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.
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.
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
Clear and bright to start, cloudier with some light rain into the day.
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
|
|
Chance of precipitation (at 800m) |
<05% | <05% | <05% | <05% | 30% | 60% | 80% | 80% |
Wind direction and speed (mph)
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m |
NE
16
|
NE
9
|
W
8
|
W
15
|
W
20
|
W
23
|
SW
27
|
W
31
|
| 600m |
NE
8
|
E
6
|
SW
6
|
SW
12
|
W
16
|
SW
18
|
SW
18
|
W
20
|
| 300m |
NE
3
|
SE
3
|
SW
3
|
SW
9
|
W
12
|
SW
13
|
SW
13
|
W
14
|
| Valley |
NE
3
|
SE
3
|
S
4
|
W
9
|
W
12
|
SW
13
|
SW
14
|
W
15
|
Wind gust (mph)
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m | 20 | 11 | 10 | 20 | 27 | 31 | 35 | 40 |
| 600m | 11 | 7 | 8 | 17 | 23 | 25 | 25 | 28 |
| 300m | 9 | 5 | 6 | 14 | 21 | 22 | 23 | 26 |
| Valley | 9 | 5 | 7 | 15 | 21 | 22 | 25 | 28 |
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m |
0°
|
0°
|
0°
|
1°
|
2°
|
3°
|
4°
|
4°
|
| 600m |
2°
|
2°
|
2°
|
4°
|
4°
|
5°
|
5°
|
6°
|
| 300m |
4°
|
3°
|
4°
|
6°
|
7°
|
7°
|
8°
|
8°
|
| Valley |
6°
|
5°
|
4°
|
8°
|
8°
|
8°
|
9°
|
10°
|
| Freezing Level |
800m
|
800m
|
800m
|
1,000m
|
1,000m
|
1,300m
|
1,500m
|
1,700m
|
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m |
-6°
|
-4°
|
-4°
|
-4°
|
-4°
|
-4°
|
-3°
|
-2°
|
| 600m |
-1°
|
-1°
|
-1°
|
-1°
|
0°
|
0°
|
1°
|
1°
|
| 300m |
3°
|
2°
|
2°
|
3°
|
4°
|
3°
|
4°
|
5°
|
| Valley |
5°
|
4°
|
3°
|
5°
|
6°
|
6°
|
6°
|
7°
|
Additional weather information
Meteorologist's view
The UV index will be moderate into the late morning, with low temperatures and notable wind-chill perhaps masking the effect of the strong sun.
Weather
Fine and frosty first thing, perhaps some shallow mist and fog in sheltered valleys but clearing quickly into the morning as temperatures rise. Cloud soon spreading from the northwest however, with strengthening westerly winds bringing spells of generally light rain during the afternoon. Rain perhaps briefly wintry over the highest tops to start and drizzle becoming locally more persistent as cloud descends into the evening to give a dull end to the day.
Chance of cloud-free hill tops
95% at dawn falling to 20% by the end of the day.
Low cloud and visibility
Largely cloud-free to start, thickening and lowering from the north and west through the afternoon with cloud bases lowering towards 500-600m by dusk and locally lower for some western slopes. Very good visibility falling to good, locally moderate in more persistent light rain and drizzle later.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Overnight cloud and rain giving way to clearing skies and scattered showers through the morning. Drier into the afternoon with plenty of sunshine but temperatures remaining on the cool side.
Chance of cloud-free hill tops
10% becoming 90% into the afternoon.
Maximum wind speed expected
NNW'ly 20-25mph gusting 40-45mph initially, easing through the day.
Temperature
- At 800m Plus 1-2 Celsius
- Valley Plus 8 becoming 11 Celsius.
- Freezing level 1500m becoming 1000m.
Low cloud and visibility
Widespread cloud down to 300-400m to start, lifting and breaking above summits into the afternoon. Visibility locally poor or very poor at height during the morning but becoming good.
Mountain weather information
Sat 20 Apr
Sunrise:
Sunset:
Most likely fine with some warm, if rather hazy sunshine after a chilly start with some mist and frost in shelter. Light northwesterly winds.
Sun 21 Apr
Sunrise:
Sunset:
A similar day to Saturday, if perhaps slightly cloudier. Light northwesterly winds.
Mon 22 Apr
Sunrise:
Sunset:
Likely cloudier with the chance of the odd shower. Light northeasterly 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.