Mountain weather
Eryri / Snowdonia Mountain weather forecast table
Confidence
High for cloudy and rather humid conditions, low for shower detail.
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.
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.
Mountain weather forecast
Cloudy, humid with showers at times.
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
Weather (at 800m) |
|
|
|
|
|
|
Chance of precipitation (at 800m) |
20% | 30% | 40% | 30% | 10% | <05% |
Wind direction and speed (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
SE
17
|
S
14
|
SW
13
|
SW
15
|
SW
19
|
SW
21
|
| 600m |
S
12
|
S
15
|
SW
15
|
SW
15
|
SW
15
|
SW
14
|
| 300m |
SE
4
|
S
9
|
SW
9
|
SW
10
|
SW
10
|
S
7
|
| Valley |
SE
4
|
S
8
|
SW
8
|
SW
9
|
SW
9
|
S
7
|
Wind gust (mph)
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m | 20 | 18 | 17 | 20 | 24 | 25 |
| 600m | 14 | 19 | 19 | 20 | 20 | 19 |
| 300m | 8 | 13 | 14 | 15 | 16 | 15 |
| Valley | 8 | 12 | 13 | 14 | 15 | 15 |
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
11°
|
9°
|
8°
|
7°
|
6°
|
5°
|
| 600m |
13°
|
10°
|
10°
|
10°
|
8°
|
7°
|
| 300m |
15°
|
13°
|
12°
|
12°
|
11°
|
9°
|
| Valley |
15°
|
14°
|
13°
|
14°
|
12°
|
10°
|
| Freezing Level |
2,700m
|
2,700m
|
2,700m
|
1,700m
|
1,400m
|
1,600m
|
Altitude above mean sea level
| Time | 06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 |
|---|---|---|---|---|---|---|
| 900m |
8°
|
6°
|
5°
|
4°
|
1°
|
0°
|
| 600m |
10°
|
8°
|
7°
|
6°
|
4°
|
3°
|
| 300m |
14°
|
12°
|
10°
|
10°
|
9°
|
7°
|
| Valley |
14°
|
13°
|
12°
|
12°
|
11°
|
9°
|
Additional weather information
Meteorologist's view
It will be rather humid through the day, so pack plenty of water when heading out onto the hills. A light waterproof would also be advised.
Weather
Isolated showers for much of the day, most of these light but low risk some could be heavy with a risk of thunder. turning drier into the evening. Rather cloudy throughout.
Chance of cloud-free hill tops
60% with cloud bases deteriorating in and around showers.
Low cloud and visibility
Mainly good, but decreasing moderate to poor in any showers with cloud bases falling to around 500metres.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Mostly dry, but rather cloudy. A risk of rain by the evening.
Chance of cloud-free hill tops
70%. Early cloud as low as 400 m over W slopes. Becoming mostly cloud free. Bases dropping to 300-400 m in rain into the evening.
Maximum wind speed expected
Mainly southerly at 10-15 mph.
Temperature
- At 800m 9 C
- Valley 14 C
- Freezing level Above summits.
Low cloud and visibility
Mainly good. Moderate at first and poor in rain later in the day.
Mountain weather information
Sun 3 May
Sunrise:
Sunset:
Locally heavy rain at first, becoming lighter and patchier into the afternoon. Cloudy throughout with peaks often shrouded.
Mon 4 May
Sunrise:
Sunset:
Rather cloudy with bright spells. Isolated showers, mainly in the afternoon. Feeling cooler than of late.
Tue 5 May
Sunrise:
Sunset:
Bright with some sunny spells. An isolated shower possible, but mainly dry. Light winds.
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.