Mountain Ash weather

The Mountain Ash weather guide shows monthly weather averages (including daytime and night-time temperatures, rainfall and hours of sunshine) for holidays in Mountain Ash, Rhondda Cynon Tall, Wales in 2026/2027.

• Mountain Ash weather averages
• Mountain Ash weather by month
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Mountain Ash weather averages

Check the Mountain Ash weather averages for each month of the year including maximum daytime and minimum night-time temperatures, monthly rainfall, number of days with rain and average daily hours of sunshine for Mountain Ash, Rhondda Cynon Tall, Wales.

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Mountain Ash weather by month

Check the weather for Mountain Ash, Rhondda Cynon Tall, Wales for a particular month by selecting from the list below. This gives the best indication of what to expect from the weather months in advance.

• January
• February
• March
• April
• May
• June
• July
• August
• September
• October
• November
• December

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Mountain Ash weather in January

The average maximum daytime temperature in Mountain Ash in January is a cold 6°C (43°F), while the average minimum night-time temperature is a cold 1°C (34°F). You can expect on average 1 hours of sunshine a day in Mountain Ash during January.

• 6
  6°C max day temperature
• 1
  1 hour of sunshine per day
• 20
  20 days with some rainfall
• 1
  1°C min night temperature
• 165
  165 mm of monthly rainfall

On average 165 mm (6.5 inches) of rain normally falls in Mountain Ash during January with rain falling on 20 days of the month.

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Mountain Ash weather in February

The average maximum daytime temperature in Mountain Ash in February is a cold 7°C (45°F), while the average minimum night-time temperature is a cold 1°C (34°F). You can expect on average 2 hours of sunshine a day in Mountain Ash during February.

• 7
  7°C max day temperature
• 2
  2 hours of sunshine per day
• 16
  16 days with some rainfall
• 1
  1°C min night temperature
• 120
  120 mm of monthly rainfall

On average 120 mm (4.7 inches) of rain normally falls in Mountain Ash during February with rain falling on 16 days of the month.

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Mountain Ash weather in March

The average maximum daytime temperature in Mountain Ash in March is a cool 9°C (48°F), while the average minimum night-time temperature is a cold 2°C (36°F). You can expect on average 3 hours of sunshine a day in Mountain Ash during March.

• 9
  9°C max day temperature
• 3
  3 hours of sunshine per day
• 18
  18 days with some rainfall
• 2
  2°C min night temperature
• 114
  114 mm of monthly rainfall

On average 114 mm (4.5 inches) of rain normally falls in Mountain Ash during March with rain falling on 18 days of the month.

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Mountain Ash weather in April

The average maximum daytime temperature in Mountain Ash in April is a cool 11°C (52°F), while the average minimum night-time temperature is a cold 4°C (39°F). You can expect on average 5 hours of sunshine a day in Mountain Ash during April.

• 11
  11°C max day temperature
• 5
  5 hours of sunshine per day
• 15
  15 days with some rainfall
• 4
  4°C min night temperature
• 86
  86 mm of monthly rainfall

On average 86 mm (3.4 inches) of rain normally falls in Mountain Ash during April with rain falling on 15 days of the month.

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Mountain Ash weather in May

The average maximum daytime temperature in Mountain Ash in May is a comfortable 15°C (59°F), while the average minimum night-time temperature is a cold 6°C (43°F). You can expect on average 6 hours of sunshine a day in Mountain Ash during May.

• 15
  15°C max day temperature
• 6
  6 hours of sunshine per day
• 14
  14 days with some rainfall
• 6
  6°C min night temperature
• 80
  80 mm of monthly rainfall

On average 80 mm (3.1 inches) of rain normally falls in Mountain Ash during May with rain falling on 14 days of the month.

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Mountain Ash weather in June

The average maximum daytime temperature in Mountain Ash in June is a comfortable 18°C (64°F), while the average minimum night-time temperature is a cool 9°C (48°F). You can expect on average 6 hours of sunshine a day in Mountain Ash during June.

• 18
  18°C max day temperature
• 6
  6 hours of sunshine per day
• 14
  14 days with some rainfall
• 9
  9°C min night temperature
• 80
  80 mm of monthly rainfall

On average 80 mm (3.1 inches) of rain normally falls in Mountain Ash during June with rain falling on 14 days of the month.

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Mountain Ash weather in July

The average maximum daytime temperature in Mountain Ash in July is a comfortable 20°C (68°F), while the average minimum night-time temperature is a cool 11°C (52°F). You can expect on average 6 hours of sunshine a day in Mountain Ash during July.

• 20
  20°C max day temperature
• 6
  6 hours of sunshine per day
• 13
  13 days with some rainfall
• 11
  11°C min night temperature
• 68
  68 mm of monthly rainfall

On average 68 mm (2.7 inches) of rain normally falls in Mountain Ash during July with rain falling on 13 days of the month.

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Mountain Ash weather in August

The average maximum daytime temperature in Mountain Ash in August is a comfortable 20°C (68°F), while the average minimum night-time temperature is a cool 11°C (52°F). You can expect on average 5 hours of sunshine a day in Mountain Ash during August.

• 20
  20°C max day temperature
• 5
  5 hours of sunshine per day
• 15
  15 days with some rainfall
• 11
  11°C min night temperature
• 97
  97 mm of monthly rainfall

On average 97 mm (3.8 inches) of rain normally falls in Mountain Ash during August with rain falling on 15 days of the month.

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Mountain Ash weather in September

The average maximum daytime temperature in Mountain Ash in September is a comfortable 17°C (63°F), while the average minimum night-time temperature is a cool 9°C (48°F). You can expect on average 4 hours of sunshine a day in Mountain Ash during September.

• 17
  17°C max day temperature
• 4
  4 hours of sunshine per day
• 15
  15 days with some rainfall
• 9
  9°C min night temperature
• 112
  112 mm of monthly rainfall

On average 112 mm (4.4 inches) of rain normally falls in Mountain Ash during September with rain falling on 15 days of the month.

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Mountain Ash weather in October

The average maximum daytime temperature in Mountain Ash in October is a cool 13°C (55°F), while the average minimum night-time temperature is a cold 7°C (45°F). You can expect on average 3 hours of sunshine a day in Mountain Ash during October.

• 13
  13°C max day temperature
• 3
  3 hours of sunshine per day
• 18
  18 days with some rainfall
• 7
  7°C min night temperature
• 138
  138 mm of monthly rainfall

On average 138 mm (5.4 inches) of rain normally falls in Mountain Ash during October with rain falling on 18 days of the month.

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Mountain Ash weather in November

The average maximum daytime temperature in Mountain Ash in November is a cool 9°C (48°F), while the average minimum night-time temperature is a cold 4°C (39°F). You can expect on average 2 hours of sunshine a day in Mountain Ash during November.

• 9
  9°C max day temperature
• 2
  2 hours of sunshine per day
• 19
  19 days with some rainfall
• 4
  4°C min night temperature
• 146
  146 mm of monthly rainfall

On average 146 mm (5.7 inches) of rain normally falls in Mountain Ash during November with rain falling on 19 days of the month.

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Mountain Ash weather in December

The average maximum daytime temperature in Mountain Ash in December is a cold 7°C (45°F), while the average minimum night-time temperature is a cold 2°C (36°F). You can expect on average 1 hours of sunshine a day in Mountain Ash during December.

• 7
  7°C max day temperature
• 1
  1 hour of sunshine per day
• 19
  19 days with some rainfall
• 2
  2°C min night temperature
• 168
  168 mm of monthly rainfall

On average 168 mm (6.6 inches) of rain normally falls in Mountain Ash during December with rain falling on 19 days of the month.

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