Mountain weather
Snowdonia Mountain weather forecast table
Confidence
High confidence for dry bright skies on Tuesday evening and of grey skies, low cloud, hill fog and a brisk breeze on Wednesday and Thursday. Low confidence of timings of cloud and rain on Wednesday and Thursday. Conditions on Thursday are particularly uncertain. Given the lead time there is fairly high confidence of dry bright weather on Friday and Saturday.
This evening forecast
Tuesday evening will be dry, with light winds, good visibility and plenty of late sunshine.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
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.
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
Low cloud, rain and strong winds in the morning. Brightening up later.
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
|
|
Chance of precipitation (at 800m) |
20% | 60% | >95% | >95% | >95% | 30% | 10% | <05% |
Wind direction and speed (mph)
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m |
SW
25
|
SW
30
|
SW
34
|
SW
34
|
W
30
|
W
29
|
W
27
|
W
28
|
| 600m |
SW
15
|
SW
19
|
SW
24
|
SW
25
|
W
23
|
W
22
|
W
19
|
W
17
|
| 300m |
SW
9
|
SW
11
|
SW
16
|
SW
17
|
W
17
|
W
16
|
W
13
|
W
10
|
| Valley |
SW
10
|
SW
11
|
SW
16
|
SW
17
|
W
17
|
W
16
|
W
14
|
W
11
|
Wind gust (mph)
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m | 30 | 37 | 44 | 44 | 41 | 39 | 35 | 35 |
| 600m | 21 | 26 | 33 | 34 | 33 | 32 | 28 | 24 |
| 300m | 19 | 22 | 30 | 31 | 30 | 28 | 23 | 21 |
| Valley | 19 | 21 | 29 | 31 | 31 | 29 | 25 | 22 |
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m |
5°
|
4°
|
6°
|
7°
|
7°
|
7°
|
7°
|
6°
|
| 600m |
8°
|
7°
|
8°
|
8°
|
9°
|
10°
|
10°
|
8°
|
| 300m |
10°
|
9°
|
9°
|
10°
|
12°
|
13°
|
12°
|
10°
|
| Valley |
11°
|
11°
|
10°
|
12°
|
14°
|
14°
|
14°
|
12°
|
| Freezing Level |
1,600m
|
1,600m
|
1,900m
|
2,000m
|
1,700m
|
1,800m
|
1,700m
|
1,600m
|
Altitude above mean sea level
| 00:00 | 03:00 | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
|---|---|---|---|---|---|---|---|---|
| 900m |
0°
|
-2°
|
-1°
|
1°
|
1°
|
2°
|
2°
|
1°
|
| 600m |
4°
|
3°
|
3°
|
4°
|
5°
|
6°
|
6°
|
5°
|
| 300m |
8°
|
7°
|
6°
|
7°
|
9°
|
10°
|
10°
|
8°
|
| Valley |
9°
|
8°
|
8°
|
9°
|
10°
|
11°
|
11°
|
10°
|
Additional weather information
Meteorologist's view
Wind speeds and temperatures in these tables look realistic, just reaching gale force on the summits. Heavy showers on Tuesday and added rain on Wednesday mean that it may be quite wet underfoot, with large puddles and bogs, and fast moving streams.
Weather
Low cloud and strong winds will move over Snowdonia from 02:00, with accompanying hill fog and drizzle. Rain will arrive from around 07:00 with some heavy spells over the next three or four hours. The rain will then gradually ease, becoming light and drizzly, but low cloud, strong winds and hill fog are likely to persist until around 13:00. The weather will be much improved after that, but it will stay breezy and the odd light shower remains possible. The evening will be bright with much less cloud but a little rain or drizzle is possible.
Chance of cloud-free hill tops
Between 00:00 and 13:00. 10% with thick low cloud covering the hills down to 200m above sea level. Between 13:00 and midnight. 80% with the odd shower cloud obscuring the highest peaks.
Low cloud and visibility
Between midnight and 13:00: Thick hill fog is likely on any hills above 200m above sea level. Although patchy, visibility is likely to be below 50m at times. In the valleys, it will be misty with rain and drizzle so visibility is likely to drop to 4000m at times. After 13:00 Good visibility is expected at all levels, with fine views of surrounding hills.
Ground conditions
Please see - https://www.eryri.llyw.cymru/visiting/walking/ground-conditions
Mountain weather information
Weather
Low cloud and strong winds will again move over Snowdonia soon after midnight, with accompanying hill fog and drizzle. These may well persist all through the day, not clearing until late afternoon. Rain is likely at times during the day, perhaps heavy for a while in the morning.
Chance of cloud-free hill tops
Between 00:00 and18:00. 10% with thick low cloud covering the hills down to 200m above sea level. Between 18:00 and midnight. 80%.
Maximum wind speed expected
Mean wind speeds of 30 mph and gusts of up to 45mph on the summits any time during the day.
Temperature
- At 800m 4C at dawn, rising to 7C in the afternoon.
- Valley 10 C at dawn, rising to 15 C in the afternoon.
- Freezing level Well above summits.
Low cloud and visibility
Between midnight and 18:00: Thick hill fog is likely on any hills above 200m above sea level. Although fog will be patchy, visibility is likely to be below 50m at times. In the valleys, it will be misty with rain and drizzle so visibility is likely to drop to 4000m at times.
Mountain weather information
Fri 27 May
Sunrise:
Sunset:
Dry and clear with warm sunshine and light winds. Maximum temperatures around 16 C in the valleys.
Sat 28 May
Sunrise:
Sunset:
Dry and clear with warm sunshine and light winds. Maximum temperatures around 17 C in the valleys.
Sun 29 May
Sunrise:
Sunset:
Probably dry and bright, but more cloudy and breezy than Saturday. Max temperatures 15C.
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 Snowdonia mountains are made up of 90 mountain peaks including the tallest mountain in Wales, Snowdon, standing at 1,085 metres.
The region can be divided into four areas with the northernmost area the most popular, including peaks such as Moel Hebog, Mynydd Mawr and the Nantlle Ridge. Many hikers tend to concentrate on Snowdon itself regarding it as a fine mountain. However it can become quite crowded, with the peak welcoming around half a million visitors every year, of which four fifths scale the peak on foot, while the remainder choose to take the train instead.
One of Snowdon’s main attractions is the sheer number and variety of paths that reach the peak. This means that everyone from mountaineering novices to climbing experts should find a way up the mountain that will suit their abilities or provide them with a sufficient test. The easiest is the Llanberis path which, being the longest, has the most shallow ascent. In contrast, the Watkin Path is widely seen as being the most demanding ascent, despite also being considered the prettiest.