Eryri / Snowdonia Mountain weather forecast table
Confidence
High for increasingly settled theme, although lower for cloud detail and for extent of morning valley fog.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Strong Sunlight
Gales
Severe Chill Effect
Poor Visibility
Mountain weather forecast
On the cloudy side with rain then showers at first, becoming brighter later. Strong winds easing.
06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|
Weather (at 800m) |
||||||
Chance of precipitation (at 800m) |
40% | 40% | 20% | 10% | <05% | 00% |
06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|
900m |
NW
34
|
NW
33
|
NW
33
|
N
32
|
N
24
|
N
22
|
600m |
NW
24
|
NW
24
|
N
26
|
N
26
|
N
17
|
NE
10
|
300m |
NW
16
|
NW
17
|
NW
18
|
N
19
|
N
12
|
NE
5
|
Valley |
NW
17
|
NW
17
|
NW
18
|
N
19
|
N
13
|
NE
6
|
06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|
900m | 42 | 42 | 43 | 41 | 30 | 26 |
600m | 32 | 32 | 34 | 35 | 23 | 15 |
300m | 27 | 27 | 30 | 32 | 21 | 13 |
Valley | 28 | 28 | 30 | 32 | 22 | 14 |
06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|
900m |
3°
|
2°
|
2°
|
3°
|
2°
|
1°
|
600m |
5°
|
5°
|
5°
|
6°
|
5°
|
3°
|
300m |
7°
|
7°
|
8°
|
8°
|
8°
|
5°
|
Valley |
8°
|
8°
|
9°
|
10°
|
9°
|
7°
|
Freezing Level |
1,300m
|
1,200m
|
1,100m
|
1,000m
|
1,000m
|
900m
|
06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|
900m |
-4°
|
-5°
|
-5°
|
-5°
|
-5°
|
-5°
|
600m |
-1°
|
-1°
|
-1°
|
0°
|
0°
|
-1°
|
300m |
3°
|
3°
|
4°
|
5°
|
4°
|
4°
|
Valley |
4°
|
5°
|
6°
|
6°
|
6°
|
5°
|
Additional weather information
Meteorologist's view
There will be a marked difference between conditions early and late, with layers advisable to react to the changes. Note however there will still be a wind chill at height, even after the sun comes out later. Gusts up to 50 mph on highest ground at first will soon ease.
Weather
Windy and on the cloudy side at first. Early rain turning to scattered showers will ease by lunchtime, as cloud gradually lifts with more breaks developing. The afternoon should see clearer skies with plenty of sunny spells. Winds will be slower to drop, however by the evening should have appreciably lowered, with temperatures dipping sharply during the evening as a result.
Chance of cloud-free hill tops
20%, increasing 80% by lunchtime.
Low cloud and visibility
Areas of cloud down to 400-500 metres at first, giving very poor visibility in cloud, with moderate visibility in showers. Cloud lifting and breaking around lunchtime, but perhaps with patches lingering on higher summits. Visibility subsequently very good.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
A chilly start, with some valley frost as well as possible shallow mist and fog. Some hazy sunshine is then expected, but cloud perhaps thickening a little around the middle of the day, although this should lie clear of the highest ground throughout. Feeling chilly.
Chance of cloud-free hill tops
90%
Maximum wind speed expected
Variable, mainly northerly, 10mph.
Temperature
- At 800m Plus 3 Celsius.
- Valley Minus 1 becoming plus 11 Celsius.
- Freezing level Around 1000 metres and rising.
Low cloud and visibility
Risk of fog in valleys early and late, else little impediment to very good visibility.
Mountain weather information
Sun 21 Apr
Relatively low confidence in cloud detail especially through this three-day period. Probably rather cloudy, perhaps with the odd spot of rain at times, although western parts perhaps more reliably dry with the best sunny spells. Light northerly or northeasterly winds. Freezing level above summits.
Mon 22 Apr
Probably rather cloudy with a little light rain or drizzle, perhaps clearing westwards later. Light winds, perhaps upslope by day and downslope by night. Freezing level above summits.
Tue 23 Apr
Perhaps a brighter day with some sunshine and light northerly or northeasterly winds. Freezing level descending to lie near higher summits.
Summit specific forecast
Mountain summit forecast map
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.