Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for an unsettled couple of days. Moderate for a transition to more settled conditions over the weekend.
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.
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.
Mountain weather forecast
Cloudy with outbreaks of heavy showery rain.
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
10% | 20% | 40% | 60% | 70% | 80% |
Wind direction and speed (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
NE
6
|
N
5
|
N
14
|
N
17
|
N
18
|
N
21
|
| 600m |
NE
4
|
N
6
|
N
12
|
N
11
|
N
12
|
N
11
|
| 300m |
W
2
|
NW
5
|
N
10
|
N
8
|
N
8
|
N
6
|
| Valley |
W
2
|
NW
5
|
N
10
|
N
7
|
N
8
|
N
6
|
Wind gust (mph)
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m | 7 | 6 | 18 | 22 | 22 | 25 |
| 600m | 5 | 8 | 16 | 15 | 16 | 15 |
| 300m | 3 | 7 | 14 | 13 | 13 | 13 |
| Valley | 3 | 7 | 15 | 13 | 13 | 13 |
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
10°
|
11°
|
10°
|
9°
|
9°
|
9°
|
| 600m |
12°
|
13°
|
13°
|
11°
|
11°
|
11°
|
| 300m |
13°
|
16°
|
15°
|
14°
|
13°
|
13°
|
| Valley |
13°
|
17°
|
16°
|
15°
|
14°
|
14°
|
| Freezing Level |
2,000m
|
2,100m
|
2,200m
|
2,400m
|
2,500m
|
2,500m
|
Altitude above mean sea level
| 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|
| 900m |
9°
|
10°
|
8°
|
6°
|
6°
|
6°
|
| 600m |
11°
|
12°
|
11°
|
9°
|
9°
|
9°
|
| 300m |
13°
|
15°
|
14°
|
12°
|
12°
|
12°
|
| Valley |
13°
|
16°
|
15°
|
14°
|
13°
|
13°
|
Additional weather information
Meteorologist's view
A good start to the day, sun protection advised. Waterproofs recommended in the afternoon. Some swollen watercourses.
Weather
Any mist and shallow fog patches will soon clear to give a dry and sunny morning. Some showers will then move in from the east around midday, turning heavy with a risk of hail and thunder in the afternoon. Showers merging into a longer spell of heavy rain for a time, before easing during the evening. Cloud lowering again into the evening.
Chance of cloud-free hill tops
80% during the early hours but generally 95% or more by mid-morning. Reduced to 40-60% in the afternoon.
Low cloud and visibility
Some mist and shallow fog patches initially but soon clearing. Bases generally above summits by day, lowering from mid-afternoon to 600-700m. Good visibility with clear views of distant hills, moderate in rain or showers, poor in cloud at elevation later.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A cloudy and murky start on Friday with low cloud covering hill tops and outbreaks of rain. Cloud lifting and breaking through the day, some brief brighter spells in the afternoon and the risk of an isolated heavy perhaps thundery shower.
Chance of cloud-free hill tops
20% initially, becoming 80% by mid-morning.
Maximum wind speed expected
Northerly 17 mph.
Temperature
- At 800m Plus 10 Celsius.
- Valley Plus 12 Celsius becoming 18 Celsius.
- Freezing level Above summits.
Low cloud and visibility
Extensive cloud down to 300-400m initially, lifting and breaking through the morning, rising above summits. Visibility poor in cloud initially, becoming generally good at all elevations later with clear views of distant hills. Perhaps briefly moderate in isolated showers.
Mountain weather information
Sat 18 May
Sunrise:
Sunset:
A brighter day but once again with a chance of heavy thundery showers. Freezing level above summits.
Sun 19 May
Sunrise:
Sunset:
Partly cloudy, with sunny intervals, mostly dry. Freezing level above summits.
Mon 20 May
Sunrise:
Sunset:
Bright initially, a chance of heavy thundery showers. Freezing level 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.