Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for the overall story of rain and cloud approaching from the west through Thursday, but moderate for the precise timing of the arrival of the leading edge. High for a gradual change to more settled conditions later in the period.
This evening forecast
Blustery showers continuing through the evening with a potential for these to be heavy at times, with some hail or thunder possible.
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.
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.
Mountain weather forecast
Drier to begin, with cloud and rain arriving from the west later.
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
|
|
Chance of precipitation (at 800m) |
30% | 20% | 10% | 10% | 10% | 30% | 60% | 70% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
SW
44
|
SW
44
|
SW
32
|
SW
28
|
SW
26
|
SW
26
|
SW
28
|
S
27
|
| 600m |
SW
31
|
SW
30
|
SW
21
|
SW
21
|
SW
21
|
SW
22
|
SW
20
|
S
20
|
| 300m |
SW
19
|
SW
19
|
SW
12
|
SW
14
|
SW
15
|
SW
15
|
S
13
|
S
13
|
| Valley |
SW
18
|
SW
19
|
SW
11
|
SW
14
|
SW
15
|
SW
15
|
S
12
|
S
12
|
Wind gust (mph)
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m | 55 | 55 | 40 | 36 | 35 | 34 | 35 | 34 |
| 600m | 41 | 40 | 29 | 29 | 29 | 30 | 27 | 27 |
| 300m | 35 | 36 | 25 | 25 | 26 | 27 | 24 | 24 |
| Valley | 34 | 36 | 24 | 24 | 25 | 26 | 22 | 23 |
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
4°
|
3°
|
3°
|
4°
|
4°
|
4°
|
4°
|
4°
|
| 600m |
6°
|
5°
|
5°
|
6°
|
7°
|
7°
|
6°
|
6°
|
| 300m |
8°
|
8°
|
7°
|
9°
|
10°
|
10°
|
9°
|
8°
|
| Valley |
10°
|
9°
|
9°
|
10°
|
11°
|
12°
|
10°
|
10°
|
| Freezing Level |
1,300m
|
1,300m
|
1,200m
|
1,300m
|
1,300m
|
1,400m
|
1,400m
|
1,600m
|
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
-4°
|
-5°
|
-4°
|
-3°
|
-2°
|
-1°
|
-2°
|
-2°
|
| 600m |
0°
|
-1°
|
0°
|
1°
|
2°
|
2°
|
2°
|
2°
|
| 300m |
4°
|
4°
|
4°
|
6°
|
6°
|
7°
|
6°
|
5°
|
| Valley |
6°
|
6°
|
6°
|
8°
|
8°
|
9°
|
8°
|
7°
|
Additional weather information
Meteorologist's view
A very mixed day ahead with multiple hazards changing through the day. Initially poor visibility will be the main hazard causing navigation to become challenging. Showers through the first part of the afternoon and patchy rain and drizzle later will require waterproof layers to be worn, with warm layers also suggested due to wind chill. Improving for a time through the afternoon with view to distant hills between any showers. Deteriorating once again through the evening.
Weather
Patchy cloud likely through much of the morning period and into the afternoon, with some brighter breaks possible. This will be accompanied by a few isolated light showers, and gusty winds on the highest peaks. Cloud is expected to increase from the southwest through the afternoon bringing outbreaks of light rain and drizzle and extensive hill fog over western and southwestern facing slopes. Wet and cloudy conditions are expected to persist until after nightfall.
Chance of cloud-free hill tops
20% gradually rising to 60% for a time through the afternoon as cloud lifts, then dropping back to 20% through the afternoon as cloud and rain approaches from the west.
Low cloud and visibility
Cloud initially obstructing hills above 500m with cloud tops then dropping down to 800m allowing for the tallest peaks to clear for a time. Cloud bases are then expected to lift and become more broken at 800m through the afternoon. Through late afternoon and into the evening cloud bases are expected to drop back down to 400-600m. Outside of any cloud visibility is expected to be good or very good, with poor or very poor visibilities within cloud or showers, deteriorating further through the late afternoon and evening.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A drier and brighter day ahead after rain and cloud gradually clears to the west. Drier and brighter thereafter with further breaks then developing through the afternoon. Potential for a light isolated shower through much of the day before dying out later. Blustery winds throughout with gale force gusts possible over the highest peaks.
Chance of cloud-free hill tops
10% gradually rising to 70% through the afternoon.
Maximum wind speed expected
Southerly or southwesterly 45-55mph
Temperature
- At 800m Plus 5 Celsius.
- Valley Plus 11 Celsius.
- Freezing level Above summits.
Low cloud and visibility
Cloud initially obstructing hills above 400-500m, Cloud bases then breaking and lifting to 800-1000ft. Poor or moderate to begin especially in and cloud or light rain and drizzle. Gradually improving through the morning to very good or good outside patchy cloud or showers which could drop the visibility to poor for a brief time.
Mountain weather information
Sat 18 Apr
Sunrise:
Sunset:
A drier and brighter day ahead as high pressure begins to develop. Still the potential for patchy cloud through the day but likely above summits. Valley mist and fog early on. Freezing level above summits.
Sun 19 Apr
Sunrise:
Sunset:
A largely dry day, with light winds. Early brighter or sunny spells are likely to turn hazy as high cloud builds, however summits are likely to remain clear. Mist and fog patches to start. Freezing level staying above summits.
Mon 20 Apr
Sunrise:
Sunset:
Another fine and dry day ahead with plenty of sunny spells throughout. This will be accompanied by light winds. Freezing level staying 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.