Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High in overall weather story, though moderate in shower details throughout the week.
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.
Mountain weather forecast
Some early brightness on Tuesday but skies tending to cloud over during the middle of the day with some outbreaks of rain possible for a time. Turning brighter again later in the afternoon. Feeling cooler than of late.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
20% | 30% | 30% | 20% | 10% | 30% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
N
18
|
N
13
|
N
13
|
N
14
|
N
14
|
N
16
|
| 600m |
N
9
|
N
12
|
N
12
|
N
12
|
N
12
|
N
6
|
| 300m |
N
5
|
N
9
|
N
10
|
N
10
|
N
9
|
N
4
|
| Valley |
N
5
|
N
9
|
N
10
|
N
10
|
N
9
|
N
4
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 21 | 17 | 17 | 18 | 18 | 21 |
| 600m | 11 | 15 | 17 | 17 | 16 | 11 |
| 300m | 11 | 13 | 15 | 15 | 14 | 10 |
| Valley | 11 | 13 | 15 | 15 | 14 | 10 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
3°
|
3°
|
3°
|
3°
|
3°
|
2°
|
| 600m |
5°
|
5°
|
6°
|
6°
|
6°
|
4°
|
| 300m |
7°
|
8°
|
8°
|
9°
|
8°
|
7°
|
| Valley |
8°
|
9°
|
10°
|
10°
|
10°
|
8°
|
| Freezing Level |
1,200m
|
1,200m
|
1,200m
|
1,200m
|
1,100m
|
1,200m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-3°
|
-2°
|
-2°
|
-1°
|
-2°
|
-3°
|
| 600m |
1°
|
2°
|
2°
|
3°
|
2°
|
2°
|
| 300m |
6°
|
6°
|
6°
|
6°
|
6°
|
6°
|
| Valley |
7°
|
7°
|
8°
|
8°
|
8°
|
7°
|
Additional weather information
Meteorologist's view
It will be feeling colder than recently, especially at height with temperatures feeling near freezing at height. UV levels will be moderate to high in any sunnier interludes so sun protection is advised.
Weather
A largely fine start to the day with some sunny intervals after dawn. Cloud will tend to thicken through the morning becoming rather overcast during the middle of the day with some outbreaks of mainly light rain. The cloud will begin to break up again during the afternoon allowing some later spells of sunshine to develop, before band of cloud approaches the park from the east during the evening.
Chance of cloud-free hill tops
90% first thing falling to 60% during the morning. Rising back to 80% during the afternoon, before falling to 40% by the end of the evening.
Low cloud and visibility
Cloud bases generally above the summits after dawn but falling to around 600m at times through the morning. Cloud bases lifting again back above the summits during the afternoon, before lowering to 500m by the end of the evening. Visibilities generally good or very good, but lowering to poor or very poor in any hill fog and perhaps temporarily moderate in any outbreaks of rain.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Patchy rain will move southwest across the park early Wednesday, before becoming drier after dawn. Turning brighter into the afternoon with some spells of sunshine developing. Skies tending to clear further into Wednesday evening. A rather cold feeling day for the time of year.
Chance of cloud-free hill tops
30% during the early hours of Wednesday but rising to 90% after dawn.
Maximum wind speed expected
Easterly 30-35mph.
Temperature
- At 800m Plus 01 Celsius, rising to plus 05 Celsius.
- Valley Plus 04 Celsius, rising to Plus 13 Celsius.
- Freezing level Above the summits.
Low cloud and visibility
Cloud bases falling to around 500m throughout the early hours, especially during any outbreaks of rain or drizzle. Bases then lifting above summits after dawn. Visibilities poor or very poor during the early hours, especially at height. Visibilities then gradually improving to very good or excellent throughout the morning.
Mountain weather information
Thu 7 May
Sunrise:
Sunset:
A mix of sunny spells and scattered showers. A small chance of the odd heavier shower. Light to moderate southerly winds.
Fri 8 May
Sunrise:
Sunset:
A similar day to Thursday with a mix of sunny spells and a scattering of showers. Feeling a little warmer with light to moderate southeasterly winds.
Sat 9 May
Sunrise:
Sunset:
A dry and bright start, but a band of rain likely to move up from the south throughout the day with scattered showers following. A risk of some heavier rain for a time. Moderate easterly 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.