Castletown weather

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

• Castletown weather averages
• Castletown weather by month
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Castletown weather averages

Check the Castletown 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 Castletown, Isle of Man.

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Castletown weather by month

Check the weather for Castletown, Isle of Man 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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Castletown weather in January

The average maximum daytime temperature in Castletown 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 2 hours of sunshine a day in Castletown during January.

• 6
  6°C max day temperature
• 2
  2 hours of sunshine per day
• 21
  21 days with some rainfall
• 1
  1°C min night temperature
• 217
  217 mm of monthly rainfall

On average 217 mm (8.5 inches) of rain normally falls in Castletown during January with rain falling on 21 days of the month.

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Castletown weather in February

The average maximum daytime temperature in Castletown 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 3 hours of sunshine a day in Castletown during February.

• 7
  7°C max day temperature
• 3
  3 hours of sunshine per day
• 17
  17 days with some rainfall
• 1
  1°C min night temperature
• 154
  154 mm of monthly rainfall

On average 154 mm (6.1 inches) of rain normally falls in Castletown during February with rain falling on 17 days of the month.

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Castletown weather in March

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

• 9
  9°C max day temperature
• 4
  4 hours of sunshine per day
• 19
  19 days with some rainfall
• 2
  2°C min night temperature
• 172
  172 mm of monthly rainfall

On average 172 mm (6.8 inches) of rain normally falls in Castletown during March with rain falling on 19 days of the month.

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Castletown weather in April

The average maximum daytime temperature in Castletown 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 6 hours of sunshine a day in Castletown during April.

• 11
  11°C max day temperature
• 6
  6 hours of sunshine per day
• 16
  16 days with some rainfall
• 4
  4°C min night temperature
• 110
  110 mm of monthly rainfall

On average 110 mm (4.3 inches) of rain normally falls in Castletown during April with rain falling on 16 days of the month.

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Castletown weather in May

The average maximum daytime temperature in Castletown in May is a comfortable 14°C (57°F), while the average minimum night-time temperature is a cold 6°C (43°F). You can expect on average 7 hours of sunshine a day in Castletown during May.

• 14
  14°C max day temperature
• 7
  7 hours of sunshine per day
• 16
  16 days with some rainfall
• 6
  6°C min night temperature
• 103
  103 mm of monthly rainfall

On average 103 mm (4.1 inches) of rain normally falls in Castletown during May with rain falling on 16 days of the month.

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Castletown weather in June

The average maximum daytime temperature in Castletown in June 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 7 hours of sunshine a day in Castletown during June.

• 17
  17°C max day temperature
• 7
  7 hours of sunshine per day
• 15
  15 days with some rainfall
• 9
  9°C min night temperature
• 107
  107 mm of monthly rainfall

On average 107 mm (4.2 inches) of rain normally falls in Castletown during June with rain falling on 15 days of the month.

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Castletown weather in July

The average maximum daytime temperature in Castletown in July is a comfortable 19°C (66°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 Castletown during July.

• 19
  19°C max day temperature
• 6
  6 hours of sunshine per day
• 15
  15 days with some rainfall
• 11
  11°C min night temperature
• 113
  113 mm of monthly rainfall

On average 113 mm (4.4 inches) of rain normally falls in Castletown during July with rain falling on 15 days of the month.

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Castletown weather in August

The average maximum daytime temperature in Castletown in August is a comfortable 18°C (64°F), while the average minimum night-time temperature is a cool 10°C (50°F). You can expect on average 6 hours of sunshine a day in Castletown during August.

• 18
  18°C max day temperature
• 6
  6 hours of sunshine per day
• 17
  17 days with some rainfall
• 10
  10°C min night temperature
• 139
  139 mm of monthly rainfall

On average 139 mm (5.5 inches) of rain normally falls in Castletown during August with rain falling on 17 days of the month.

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Castletown weather in September

The average maximum daytime temperature in Castletown in September is a comfortable 16°C (61°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 Castletown during September.

• 16
  16°C max day temperature
• 4
  4 hours of sunshine per day
• 17
  17 days with some rainfall
• 9
  9°C min night temperature
• 175
  175 mm of monthly rainfall

On average 175 mm (6.9 inches) of rain normally falls in Castletown during September with rain falling on 17 days of the month.

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Castletown weather in October

The average maximum daytime temperature in Castletown in October is a cool 13°C (55°F), while the average minimum night-time temperature is a cold 6°C (43°F). You can expect on average 3 hours of sunshine a day in Castletown during October.

• 13
  13°C max day temperature
• 3
  3 hours of sunshine per day
• 20
  20 days with some rainfall
• 6
  6°C min night temperature
• 218
  218 mm of monthly rainfall

On average 218 mm (8.6 inches) of rain normally falls in Castletown during October with rain falling on 20 days of the month.

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Castletown weather in November

The average maximum daytime temperature in Castletown in November is a cool 9°C (48°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 Castletown during November.

• 9
  9°C max day temperature
• 2
  2 hours of sunshine per day
• 21
  21 days with some rainfall
• 3
  3°C min night temperature
• 213
  213 mm of monthly rainfall

On average 213 mm (8.4 inches) of rain normally falls in Castletown during November with rain falling on 21 days of the month.

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Castletown weather in December

The average maximum daytime temperature in Castletown 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 Castletown during December.

• 7
  7°C max day temperature
• 1
  1 hour of sunshine per day
• 21
  21 days with some rainfall
• 2
  2°C min night temperature
• 236
  236 mm of monthly rainfall

On average 236 mm (9.3 inches) of rain normally falls in Castletown during December with rain falling on 21 days of the month.

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