Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High confidence in the unsettled pattern of weather, but lower confidence in the detail of the showers and risk of storms on Thursday.
This evening forecast
Fine and dry through the evening with good spells of sunshine. Light variable winds, strengthening to moderate and becoming easterly by midnight.
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.
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.
Thunderstorms
Lightning is a significant mountain hazard which can result in serious injury or death. Mountain terrain often leaves one highly exposed to lightning strikes. Hail may give unpleasant conditions with torrential rain and localised flash flooding also possible, mainly in Summer months.
Heavy Persistent Rain
Heavy and persistent rain can lead to drenched clothing and footwear with waterproofs often becoming soaked through, especially if accompanied by strong winds. This can lead to significant loss of body heat and an increased likelihood of hypothermia. Terrain may turn increasingly boggy underfoot while streams can flood and become impassable. There may also be a risk of flooding in valleys or glens. If there is snow cover, a heightened avalanche hazard is possible and avalanche reports should be consulted where available.
Mountain weather forecast
Dry at first, showers for the afternoon.
| 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) |
00% | 10% | 20% | 60% | 70% | 60% | 20% | 20% |
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 |
SE
37
|
SE
36
|
SE
38
|
E
36
|
SE
34
|
S
29
|
S
28
|
S
26
|
| 600m |
SE
21
|
SE
23
|
SE
23
|
SE
24
|
SE
26
|
S
22
|
S
21
|
S
18
|
| 300m |
SE
16
|
SE
17
|
SE
18
|
SE
17
|
SE
19
|
S
15
|
S
15
|
S
10
|
| Valley |
SE
16
|
SE
18
|
SE
18
|
SE
17
|
SE
19
|
S
15
|
S
15
|
S
11
|
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 | 47 | 45 | 46 | 42 | 42 | 36 | 35 | 32 |
| 600m | 32 | 34 | 33 | 30 | 34 | 28 | 27 | 24 |
| 300m | 29 | 32 | 32 | 30 | 31 | 26 | 25 | 20 |
| Valley | 29 | 32 | 33 | 31 | 31 | 26 | 25 | 20 |
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
13°
|
13°
|
13°
|
12°
|
13°
|
13°
|
12°
|
11°
|
| 600m |
16°
|
16°
|
16°
|
15°
|
16°
|
15°
|
14°
|
13°
|
| 300m |
17°
|
16°
|
16°
|
17°
|
18°
|
17°
|
15°
|
15°
|
| Valley |
18°
|
17°
|
17°
|
18°
|
20°
|
18°
|
16°
|
16°
|
| Freezing Level |
3,200m
|
3,100m
|
3,000m
|
3,400m
|
3,300m
|
3,100m
|
2,900m
|
2,600m
|
Altitude above mean sea level
| Time | 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|---|---|
| 900m |
7°
|
7°
|
7°
|
7°
|
8°
|
8°
|
8°
|
7°
|
| 600m |
12°
|
11°
|
11°
|
11°
|
11°
|
11°
|
10°
|
10°
|
| 300m |
14°
|
12°
|
12°
|
13°
|
14°
|
15°
|
13°
|
13°
|
| Valley |
14°
|
13°
|
14°
|
14°
|
16°
|
16°
|
14°
|
14°
|
Additional weather information
Meteorologist's view
Decent hill-walking conditions at first on Thursday, with sunny spells and high UV levels meaning that appropriate sun protection should be used. However, this will turn in the afternoon with a risk of heavy persistent rain, thunderstorms and hail. Waterproofs maybe required and all walkers should have a plan of what to do if there is hail or thunder.
Weather
Dry at first with some sunny spells possible. Cloud thickening through the morning to give a risk of showers. These may be light at first but through the afternoon they will become more frequent and may turn heavy at times with a risk of thunder and hail. These easing through the evening to become generally dry overnight.
Chance of cloud-free hill tops
>95% at first becoming 40% in the afternoon.
Low cloud and visibility
Cloud bases above summits at first, but as showers develop through the day bases down to 300-400m are expected, with a low risk of bases getting down to 100-200m for short periods in the afternoon or evening. Visibility generally good at first, becoming moderate or poor in the showers through the afternoon, and very poor in the low cloud.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Cloudy but mainly dry, with a small chance of some light rain or drizzle at times in the morning. Strong, gusty winds in the morning, particularly over the summits. Fine and dry through the afternoon with sunny spells developing and winds easing.
Chance of cloud-free hill tops
Generally 90%, but going down to 60% in any rain or drizzle.
Maximum wind speed expected
20-25mph with gusts 35-40mph.
Temperature
- At 800m Plus 10 becoming Plus 12.
- Valley Plus 14 becoming Plus 16.
- Freezing level Above summits.
Low cloud and visibility
Cloud bases will be mainly above the summits, but could temporarily go down to 300-500m in any rain or drizzle. Visibility will be good, but poor in any low cloud and moderate to poor in any rain.
Mountain weather information
Sat 14 Jun
Sunrise:
Sunset:
Showery rain possible through the day, heavy at times with a risk of hail and thunder. This should largely clear up overnight.
Sun 15 Jun
Sunrise:
Sunset:
Cloudy but mainly dry through the morning, with a low chance of some patchy light rain at times. Staying dry in the afternoon with some sunny spells developing.
Mon 16 Jun
Sunrise:
Sunset:
Breezy, with plenty of cloud and some showers or longer spells of rain.
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.