Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
Very high for a dry and settled week. Moderate for strength of winds on Tuesday and Wednesday.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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.
Mountain weather forecast
Increasingly windy but otherwise becoming fine with sunny periods.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
30% | <05% | <05% | <05% | <05% | 00% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
E
34
|
E
28
|
E
30
|
E
30
|
E
32
|
E
41
|
| 600m |
E
14
|
E
18
|
E
21
|
E
21
|
E
19
|
E
24
|
| 300m |
SE
5
|
E
10
|
E
14
|
E
14
|
E
12
|
E
13
|
| Valley |
SE
4
|
E
10
|
E
13
|
E
14
|
E
11
|
E
12
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 40 | 37 | 40 | 40 | 41 | 52 |
| 600m | 22 | 25 | 29 | 30 | 28 | 35 |
| 300m | 12 | 20 | 26 | 26 | 23 | 28 |
| Valley | 11 | 19 | 24 | 26 | 21 | 26 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
0°
|
1°
|
4°
|
5°
|
4°
|
2°
|
| 600m |
2°
|
4°
|
6°
|
8°
|
7°
|
4°
|
| 300m |
5°
|
7°
|
9°
|
11°
|
10°
|
7°
|
| Valley |
6°
|
8°
|
11°
|
12°
|
12°
|
8°
|
| Freezing Level |
900m
|
900m
|
1,000m
|
1,100m
|
1,000m
|
800m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
-8°
|
-6°
|
-3°
|
-1°
|
-2°
|
-6°
|
| 600m |
-3°
|
-1°
|
2°
|
4°
|
3°
|
-1°
|
| 300m |
3°
|
4°
|
6°
|
8°
|
8°
|
4°
|
| Valley |
4°
|
6°
|
8°
|
10°
|
9°
|
6°
|
Additional weather information
Meteorologist's view
Winds strengthening through the day giving considerable buffeting on summits and ridges exposed to the strong easterly winds. Frequent gusts of 40 to 50 mph are likely from mid-afternoon, especially across the Carneddau but isolated gusts of similar strength can be expected on the summit of Yr Wyddfa and across the Glyderau later. This will make walking arduous later in the day and increase the level of risk when traversing ridges such as Crib Goch. Despite the strong April sunshine providing some warmth, the winds will make it feel well below freezing on the highest summits early and late in the day.
Weather
Cloudy first thing with the odd brief light shower possible. Clear spells are likely too with cloud amounts reducing through the morning to leave increasingly prolonged sunny periods by Tuesday afternoon. Some high cloud may give a hazier look to the sunshine at times. Turning increasingly windy but feeling warm where sheltered from the easterly wind.
Chance of cloud-free hill tops
60% becoming 95%.
Low cloud and visibility
Periods of cloud above 600-800m until mid-morning, steadily lifting becoming patches above 900m by late morning and clearing all summits by early afternoon. Visibility will be very poor in cloud/hill fog but otherwise expect very good visibility albeit with a slight haze making faraway landmarks somewhat fuzzy to see.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Very windy with summit gales likely. Another fine and largely sunny day is in store, albeit with the sunshine a little hazy at times. Feeling cold on the summits, especially early and late in the day. Very low humidity air arriving so staying hydrated is recommended.
Chance of cloud-free hill tops
70% becoming 100% by mid-morning.
Maximum wind speed expected
Easterly 45-55 mph.
Temperature
- At 800m Plus 1 Celsius rising to plus 11 Celsius.
- Valley Plus 3 Celsius rising to plus 17 Celsius.
- Freezing level Above the summits.
Low cloud and visibility
Banks of cloud between 650m and 800m may affect east facing slopes in the east of the National Park, this soon dispersing to leave all summits cloud free by mid-morning. Visibility will be very poor in cloud/hill fog but otherwise expect very good visibility albeit with a slight haze making faraway landmarks somewhat fuzzy to see.
Mountain weather information
Thu 23 Apr
Sunrise:
Sunset:
Patchy cloud clearing to leave a sunny day. Winds easing very slightly but staying fresh to strong easterly. Freezing level above summits. UV levels becoming high for a time.
Fri 24 Apr
Sunrise:
Sunset:
A similar day ahead with patchy cloud clearing to leave a sunny day. Much lighter winds than previous days, generally light to moderate easterly. Feeling warmer with freezing level above summits.
Sat 25 Apr
Sunrise:
Sunset:
Staying similar with light to moderate easterly winds and mostly sunny and warm once any valley mist and fog has cleared. A small chance of an afternoon shower. Freezing level above the 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.