Eryri / Snowdonia Mountain weather forecast table
Confidence
High for unsettled main theme and rising temperatures, but notably low for detail given very weak progression of inbound weather systems.
Mountain weather hazards
Hazards apply at or above 300m, reflecting the more severe conditions which can occur at altitude.
Strong Sunlight
Severe Chill Effect
Poor Visibility
Mountain weather forecast
Friday fine for a time after fog and frost, isolated wintry showers developing later.
06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|
Weather (at 800m) |
||||||
Chance of precipitation (at 800m) |
20% | 10% | 30% | 40% | 20% | 20% |
06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|
900m |
E
17
|
E
15
|
E
10
|
NE
12
|
NE
15
|
E
17
|
600m |
E
12
|
E
13
|
E
11
|
NE
12
|
NE
11
|
E
12
|
300m |
E
6
|
E
12
|
E
8
|
NE
9
|
NE
9
|
E
10
|
Valley |
E
6
|
E
11
|
E
8
|
NE
10
|
NE
9
|
E
10
|
06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|
900m | 23 | 20 | 14 | 17 | 21 | 24 |
600m | 18 | 18 | 15 | 17 | 16 | 20 |
300m | 12 | 17 | 13 | 15 | 16 | 19 |
Valley | 12 | 17 | 14 | 17 | 16 | 18 |
06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|
900m |
-2°
|
-1°
|
2°
|
1°
|
1°
|
0°
|
600m |
1°
|
2°
|
4°
|
4°
|
3°
|
2°
|
300m |
3°
|
5°
|
7°
|
6°
|
6°
|
4°
|
Valley |
4°
|
6°
|
8°
|
7°
|
7°
|
6°
|
Freezing Level |
500m
|
500m
|
600m
|
800m
|
800m
|
800m
|
06:00 | 09:00 | 12:00 | 15:00 | 18:00 | 21:00 | |
---|---|---|---|---|---|---|
900m |
-8°
|
-8°
|
-3°
|
-4°
|
-5°
|
-6°
|
600m |
-4°
|
-3°
|
0°
|
0°
|
0°
|
-2°
|
300m |
0°
|
1°
|
5°
|
4°
|
3°
|
1°
|
Valley |
2°
|
3°
|
6°
|
5°
|
5°
|
3°
|
Additional weather information
Meteorologist's view
The UV index will be moderate, and lower than average temperatures coupled with the breeze may render the Sun's strength deceptive.
Weather
Cold with a hard frost in valleys and some freezing fog patches locally. Fine into daybreak, with local fog dispersing and some hazy sunny spells developing for a time. Fair weather cloud will build into the afternoon to the extent of producing a few snow showers above around 500 metres, with these mostly light but perhaps the odd heavier one in the east. Becoming drier but cloudier into the evening, with temperatures again falling sharply.
Chance of cloud-free hill tops
40 improving 90% by mid-morning.
Low cloud and visibility
Visibility generally very good, but notable deteriorations in snow showers and some locally poor visibility in valleys first thing.
Ground conditions
Please see - https://yrwyddfa.live/
Mountain weather information
Weather
Low confidence relative to the period. Probably a fine start with the best of any limited hazy sunshine in the north as cloud and rain stall at a distance to the south, although note high uncertainty. Probably tending to become cloudier with time, and with an attendant risk of some showery rain and summit snow later on.
Chance of cloud-free hill tops
30%
Maximum wind speed expected
Northeasterly 30mph easing.
Temperature
- At 800m Zero becoming plus 2 Celsius.
- Valley Minus 2 becoming plus 11 Celsius.
- Freezing level Sub-zero in valleys at first, else 800 metres rising to around the highest ground.
Low cloud and visibility
Good visibility in the main, but broken cloud probably persisting around 800 metres.
Mountain weather information
Sun 28 Apr
Note relatively low confidence in details through this three-day period. Sunday perhaps fine but cloudy, as persistent and occasionally heavy rain probably passes remote from the east of the Park. Light and variable, perhaps downslope winds early on, increasing moderate southwesterly later. Freezing level around the highest ground and rising.
Mon 29 Apr
Probably a brighter day, but with strong winds and a chance of rain later. Strong southwest, later southerly winds. Freezing level clear of all summits.
Tue 30 Apr
Becoming more unsettled again, with showers or longer spells of rain arriving on a moderate southeasterly wind. Freezing level clear of all 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.