Altarnum weather

The Altarnum weather guide shows monthly weather averages (including daytime and night-time temperatures, rainfall and hours of sunshine) for holidays in Altarnum, Cornwall, England in 2026/2027.

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Altarnum weather averages

Check the Altarnum 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 Altarnum, Cornwall, England.

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Altarnum weather by month

Check the weather for Altarnum, Cornwall, England 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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Altarnum weather in January

The average maximum daytime temperature in Altarnum in January is a cool 8°C (46°F), while the average minimum night-time temperature is a cold 3°C (37°F). You can expect on average 2 hours of sunshine a day in Altarnum during January.

• 8
  8°C max day temperature
• 2
  2 hours of sunshine per day
• 20
  20 days with some rainfall
• 3
  3°C min night temperature
• 159
  159 mm of monthly rainfall

On average 159 mm (6.3 inches) of rain normally falls in Altarnum during January with rain falling on 20 days of the month.

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Altarnum weather in February

The average maximum daytime temperature in Altarnum in February is a cool 8°C (46°F), while the average minimum night-time temperature is a cold 3°C (37°F). You can expect on average 3 hours of sunshine a day in Altarnum during February.

• 8
  8°C max day temperature
• 3
  3 hours of sunshine per day
• 17
  17 days with some rainfall
• 3
  3°C min night temperature
• 114
  114 mm of monthly rainfall

On average 114 mm (4.5 inches) of rain normally falls in Altarnum during February with rain falling on 17 days of the month.

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Altarnum weather in March

The average maximum daytime temperature in Altarnum in March 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 4 hours of sunshine a day in Altarnum during March.

• 9
  9°C max day temperature
• 4
  4 hours of sunshine per day
• 18
  18 days with some rainfall
• 4
  4°C min night temperature
• 107
  107 mm of monthly rainfall

On average 107 mm (4.2 inches) of rain normally falls in Altarnum during March with rain falling on 18 days of the month.

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Altarnum weather in April

The average maximum daytime temperature in Altarnum in April is a cool 12°C (54°F), while the average minimum night-time temperature is a cold 5°C (41°F). You can expect on average 6 hours of sunshine a day in Altarnum during April.

• 12
  12°C max day temperature
• 6
  6 hours of sunshine per day
• 14
  14 days with some rainfall
• 5
  5°C min night temperature
• 77
  77 mm of monthly rainfall

On average 77 mm (3 inches) of rain normally falls in Altarnum during April with rain falling on 14 days of the month.

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Altarnum weather in May

The average maximum daytime temperature in Altarnum in May is a comfortable 15°C (59°F), while the average minimum night-time temperature is a cold 7°C (45°F). You can expect on average 7 hours of sunshine a day in Altarnum during May.

• 15
  15°C max day temperature
• 7
  7 hours of sunshine per day
• 13
  13 days with some rainfall
• 7
  7°C min night temperature
• 75
  75 mm of monthly rainfall

On average 75 mm (3 inches) of rain normally falls in Altarnum during May with rain falling on 13 days of the month.

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Altarnum weather in June

The average maximum daytime temperature in Altarnum in June is a comfortable 17°C (63°F), while the average minimum night-time temperature is a cool 10°C (50°F). You can expect on average 7 hours of sunshine a day in Altarnum during June.

• 17
  17°C max day temperature
• 7
  7 hours of sunshine per day
• 13
  13 days with some rainfall
• 10
  10°C min night temperature
• 84
  84 mm of monthly rainfall

On average 84 mm (3.3 inches) of rain normally falls in Altarnum during June with rain falling on 13 days of the month.

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Altarnum weather in July

The average maximum daytime temperature in Altarnum in July is a comfortable 19°C (66°F), while the average minimum night-time temperature is a cool 12°C (54°F). You can expect on average 7 hours of sunshine a day in Altarnum during July.

• 19
  19°C max day temperature
• 7
  7 hours of sunshine per day
• 13
  13 days with some rainfall
• 12
  12°C min night temperature
• 77
  77 mm of monthly rainfall

On average 77 mm (3 inches) of rain normally falls in Altarnum during July with rain falling on 13 days of the month.

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Altarnum weather in August

The average maximum daytime temperature in Altarnum in August is a comfortable 19°C (66°F), while the average minimum night-time temperature is a cool 12°C (54°F). You can expect on average 6 hours of sunshine a day in Altarnum during August.

• 19
  19°C max day temperature
• 6
  6 hours of sunshine per day
• 14
  14 days with some rainfall
• 12
  12°C min night temperature
• 99
  99 mm of monthly rainfall

On average 99 mm (3.9 inches) of rain normally falls in Altarnum during August with rain falling on 14 days of the month.

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Altarnum weather in September

The average maximum daytime temperature in Altarnum in September is a comfortable 17°C (63°F), while the average minimum night-time temperature is a cool 10°C (50°F). You can expect on average 5 hours of sunshine a day in Altarnum during September.

• 17
  17°C max day temperature
• 5
  5 hours of sunshine per day
• 15
  15 days with some rainfall
• 10
  10°C min night temperature
• 109
  109 mm of monthly rainfall

On average 109 mm (4.3 inches) of rain normally falls in Altarnum during September with rain falling on 15 days of the month.

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Altarnum weather in October

The average maximum daytime temperature in Altarnum in October is a comfortable 14°C (57°F), while the average minimum night-time temperature is a cool 8°C (46°F). You can expect on average 3 hours of sunshine a day in Altarnum during October.

• 14
  14°C max day temperature
• 3
  3 hours of sunshine per day
• 18
  18 days with some rainfall
• 8
  8°C min night temperature
• 140
  140 mm of monthly rainfall

On average 140 mm (5.5 inches) of rain normally falls in Altarnum during October with rain falling on 18 days of the month.

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Altarnum weather in November

The average maximum daytime temperature in Altarnum in November is a cool 11°C (52°F), while the average minimum night-time temperature is a cold 5°C (41°F). You can expect on average 2 hours of sunshine a day in Altarnum during November.

• 11
  11°C max day temperature
• 2
  2 hours of sunshine per day
• 19
  19 days with some rainfall
• 5
  5°C min night temperature
• 151
  151 mm of monthly rainfall

On average 151 mm (5.9 inches) of rain normally falls in Altarnum during November with rain falling on 19 days of the month.

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Altarnum weather in December

The average maximum daytime temperature in Altarnum in December 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 Altarnum during December.

• 9
  9°C max day temperature
• 2
  2 hours of sunshine per day
• 20
  20 days with some rainfall
• 4
  4°C min night temperature
• 168
  168 mm of monthly rainfall

On average 168 mm (6.6 inches) of rain normally falls in Altarnum during December with rain falling on 20 days of the month.

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