Mountain Ash (Rhondda Cynon Taf) weather

Forecast days

Yellow weather warning.
Sunrise iconSunrise:
Sunset iconSunset:
L UV
L Pollution
No pollen data.

7 day forecast for Mountain Ash

Today (17 September 2025)
Time
01:00
02:00
03:00
04:00
05:00
06:00
07:00
08:00
09:00
10:00
11:00
12:00
13:00
14:00
15:00
16:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
Weather symbols Heavy rain Heavy rain Heavy rain Heavy rain Heavy rain Heavy rain Heavy rain Heavy rain Heavy rain Heavy rain Heavy rain Heavy rain Heavy rain Heavy rain Light rain Light rain Light rain Heavy rain Light rain Light rain Light rain Light rain Light rain
Chance of precipitation
≥95%
≥95%
≥95%
≥95%
≥95%
≥95%
≥95%
≥95%
≥95%
≥95%
≥95%
90%
90%
90%
90%
80%
80%
70%
70%
80%
80%
80%
80%
Temperature
13°
13°
13°
13°
14°
14°
14°
15°
16°
16°
17°
17°
17°
18°
18°
18°
18°
17°
17°
17°
17°
17°
17°
Feels like temperature (°C)
12°
12°
12°
12°
12°
13°
13°
13°
14°
15°
15°
16°
16°
16°
16°
17°
17°
17°
16°
16°
16°
16°
16°
Wind direction and speed
S
6
S
6
S
7
S
7
S
7
S
8
SSW
9
SW
11
SW
12
SW
12
SW
13
SW
12
SW
12
WSW
12
WSW
12
WSW
11
WSW
10
WSW
10
WSW
9
WSW
8
WSW
8
WSW
8
WSW
8
Wind gust (mph)
19
20
20
22
23
25
34
35
36
36
36
35
34
34
32
31
29
27
26
24
23
22
22
Visibility
M
M
M
P
P
P
M
P
P
M
M
M
M
M
M
M
M
M
M
M
M
M
M
Humidity
97%
98%
98%
98%
97%
97%
98%
98%
98%
98%
97%
97%
97%
97%
98%
97%
97%
97%
98%
98%
98%
98%
98%
UV - - - - - 1 1 1 1 1 1 1 1 2 2 1 1 1 1 - - - -
Thursday (18 September 2025)
Time
00:00
01:00
02:00
03:00
04:00
05:00
06:00
07:00
08:00
09:00
10:00
11:00
12:00
13:00
14:00
15:00
16:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
Weather symbols Light rain Light rain Light rain Light rain Light rain Light rain Light rain Light rain Light rain Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast
Chance of precipitation
90%
80%
80%
90%
90%
90%
80%
70%
60%
50%
30%
20%
20%
10%
10%
10%
10%
10%
<5%
10%
10%
10%
10%
10%
Temperature (°C)
17°
17°
17°
17°
17°
17°
17°
17°
17°
17°
17°
18°
19°
19°
19°
19°
20°
19°
19°
18°
18°
17°
17°
17°
Feels like temperature (°C)
16°
16°
16°
16°
16°
16°
16°
16°
15°
16°
16°
17°
17°
18°
18°
18°
18°
18°
18°
18°
17°
17°
17°
17°
Wind direction and speed (mph)
SW
8
SW
8
SW
8
SW
9
SW
10
SW
10
SW
10
SW
10
SW
10
SW
10
SW
10
SW
10
SW
11
SW
11
SW
11
SW
11
SW
11
SW
10
SW
9
SW
8
SSW
7
SSW
6
SSW
6
SSW
6
Wind gust (mph)
21
22
25
29
30
31
31
30
29
29
31
32
32
33
33
32
30
28
26
23
20
18
18
16
Visibility (description)
M
M
M
M
M
M
M
M
M
M
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
Humidity
98%
98%
98%
99%
99%
98%
98%
97%
96%
95%
94%
90%
87%
85%
85%
84%
83%
84%
86%
87%
89%
91%
91%
91%
UV - - - - - - 1 1 1 1 1 1 2 2 2 2 1 1 1 1 - - - -
Friday (19 September 2025)
Time
00:00
01:00
02:00
03:00
04:00
05:00
06:00
07:00
08:00
09:00
10:00
11:00
12:00
13:00
14:00
15:00
16:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
Weather symbols Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Overcast Cloudy Cloudy Cloudy Cloudy Cloudy Cloudy Cloudy Cloudy Cloudy Cloudy Cloudy Cloudy
Chance of precipitation
10%
10%
10%
<5%
10%
10%
10%
10%
20%
20%
20%
20%
30%
30%
30%
30%
30%
30%
40%
40%
40%
40%
40%
50%
Temperature (°C)
16°
16°
16°
16°
16°
15°
15°
15°
15°
16°
16°
17°
18°
18°
19°
19°
19°
18°
18°
17°
17°
16°
16°
15°
Feels like temperature (°C)
16°
16°
16°
16°
16°
16°
15°
15°
15°
15°
16°
17°
18°
18°
18°
19°
19°
18°
18°
18°
17°
16°
16°
16°
Wind direction and speed (mph)
SSW
6
SSW
5
S
5
S
5
S
4
S
4
S
4
S
4
S
4
S
5
S
6
S
6
SSW
6
SSW
7
SSW
7
SW
7
SW
7
SW
6
SW
6
SW
5
WSW
4
WSW
3
WSW
3
WSW
4
Wind gust (mph)
15
14
12
11
10
9
9
9
12
14
16
17
18
18
18
18
17
15
13
11
8
7
7
7
Visibility (description)
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
VG
Humidity
91%
91%
92%
93%
93%
94%
94%
94%
94%
92%
91%
87%
85%
84%
80%
81%
84%
85%
88%
92%
93%
94%
95%
95%
UV - - - - - - 1 1 1 1 1 2 3 2 2 2 1 1 1 1 - - - -
Saturday (20 September 2025)
Time
00:00
01:00
02:00
03:00
04:00
05:00
06:00
07:00
08:00
09:00
10:00
11:00
12:00
13:00
14:00
15:00
16:00
17:00
18:00
19:00
20:00
21:00
22:00
23:00
Weather symbols Cloudy Cloudy Cloudy Cloudy Light rain Light rain Light rain Light rain Light rain Light rain Light rain Light shower day Light shower day Light shower day Light shower day Light shower day Sunny intervals Sunny intervals Sunny intervals Partly cloudy night Partly cloudy night Partly cloudy night Partly cloudy night Partly cloudy night
Chance of precipitation
40%
40%
50%
50%
60%
60%
60%
60%
60%
50%
50%
50%
60%
70%
60%
50%
50%
40%
40%
40%
30%
30%
30%
30%
Temperature (°C)
15°
15°
15°
14°
14°
14°
14°
13°
13°
14°
14°
15°
15°
15°
16°
16°
16°
15°
15°
14°
13°
13°
12°
12°
Feels like temperature (°C)
15°
15°
15°
15°
14°
14°
14°
13°
13°
13°
14°
14°
15°
14°
15°
15°
15°
14°
14°
13°
12°
12°
12°
11°
Wind direction and speed (mph)
WSW
3
WSW
3
WSW
3
WSW
3
WSW
3
W
3
W
4
W
3
W
4
WNW
5
WSW
5
SW
6
W
7
W
7
W
8
W
8
W
8
WNW
7
W
7
WNW
6
WNW
5
WNW
5
WNW
5
NW
5
Wind gust (mph)
6
6
5
5
7
7
7
7
9
12
14
17
19
20
20
19
18
19
18
15
11
10
10
10
Visibility (description)
VG
VG
VG
VG
G
G
G
G
G
VG
VG
VG
E
E
E
E
E
E
E
E
E
E
E
E
Humidity
95%
95%
95%
96%
96%
96%
95%
96%
95%
93%
91%
90%
89%
84%
80%
81%
75%
74%
77%
82%
86%
87%
89%
89%
UV - - - - - - 1 1 1 1 1 2 2 3 3 2 2 1 1 1 - - - -
Sunday (21 September 2025)
Time
00:00
01:00
04:00
07:00
10:00
13:00
16:00
19:00
22:00
Weather symbols Partly cloudy night Partly cloudy night Partly cloudy night Sunny intervals Cloudy Cloudy Sunny intervals Cloudy Cloudy
Chance of precipitation
40%
40%
30%
40%
40%
30%
20%
20%
10%
Temperature (°C)
12°
11°
10°
10°
12°
13°
13°
11°
10°
Feels like temperature (°C)
11°
11°
10°
10°
11°
11°
10°
Wind direction and speed (mph)
WNW
5
WNW
5
NW
5
NNW
6
N
9
N
10
N
10
N
8
N
6
Wind gust (mph)
10
10
11
20
26
26
25
17
14
Visibility (description)
E
E
VG
VG
VG
VG
VG
VG
VG
Humidity
90%
90%
89%
89%
80%
69%
64%
69%
74%
UV - - - 1 2 3 1 1 -
Monday (22 September 2025)
Time
01:00
04:00
07:00
10:00
13:00
16:00
19:00
22:00
Weather symbols Cloudy Partly cloudy night Sunny intervals Sunny intervals Cloudy Sunny intervals Partly cloudy night Partly cloudy night
Chance of precipitation
10%
10%
10%
10%
10%
10%
10%
<5%
Temperature (°C)
11°
13°
14°
12°
10°
Feels like temperature (°C)
12°
12°
10°
Wind direction and speed (mph)
N
6
NNE
5
NNE
5
NNE
7
NE
9
NE
9
NE
7
NNE
5
Wind gust (mph)
11
10
14
20
21
19
12
10
Visibility (description)
VG
VG
VG
VG
VG
VG
VG
VG
Humidity
76%
79%
80%
68%
57%
54%
63%
72%
UV - - 1 2 4 2 1 -
Tuesday (23 September 2025)
Time
01:00
04:00
07:00
10:00
13:00
16:00
19:00
22:00
Weather symbols Partly cloudy night Partly cloudy night Sunny intervals Sunny intervals Cloudy Sunny intervals Partly cloudy night Partly cloudy night
Chance of precipitation
<5%
10%
10%
10%
10%
10%
10%
10%
Temperature (°C)
11°
14°
15°
13°
11°
Feels like temperature (°C)
10°
12°
13°
11°
10°
Wind direction and speed (mph)
NNE
5
NNE
5
NNE
5
NNE
7
NE
9
NE
8
NNE
7
NNE
6
Wind gust (mph)
8
7
10
17
19
18
12
11
Visibility (description)
VG
VG
VG
VG
VG
VG
VG
VG
Humidity
78%
81%
83%
73%
61%
58%
68%
77%
UV - - 1 2 4 1 1 -

UK video forecast

Mountain Ash weather map

View the weather with our interactive map

Loading map...
WARNING
Flood alerts icon
Flood alerts in force for Wales
Flood alerts in force for Wales

Wales weather forecast

Headline:

Remaining changeable with rain tonight.

This Evening and Tonight:

Cloudy this evening then turning increasingly wet and windy overnight with a band of heavy and persistent rain pushing eastwards. Rain most persistent over the mountains, with flooding possible. Mild overnight. Minimum temperature 11 °C.

Wednesday:

Heavy, persistent rain clearing eastwards through the morning, though remaining cloudy with outbreaks of patchy rain and drizzle throughout the day, turning heavy at times over the hills. Breezy. Maximum temperature 18 °C.

Outlook for Thursday to Saturday:

Remaining changeable with showers or longer spells of rain at times, though brighter interludes are possible. Often breezy. A little milder and more humid by the end of the week.

Updated:

UK long range weather forecast

More from the Met Office