Castle Island Weather, Climate and Best Time to Visit
Data source:Meteostat Update date:2025-09
Castle Island year round climate
Spring (March–May): 5.2–15.6°C on average, mild climate, with more rainfall in March, gradually becoming comfortable from April to May. Common activities: Outdoor walks, cycling. Suggested clothing: Light jacket, long-sleeved shirt, comfortable shoes.
Summer (June–August): 20.1–24.6°C on average, warm and humid, moderate rainfall. Common activities: Beach activities, water sports. Suggested clothing: Light and breathable clothing, hat, sunscreen.
Autumn (September–November): 8.3–19.0°C on average, pleasant climate, reduced rainfall. Common activities: Hiking, viewing autumn leaves (depending on tree species). Suggested clothing: Comfortable long-sleeved shirts, light jacket.
Winter (December–February): 0.5–3.3°C on average, cold, more rainfall, possible snowfall. Common activities: Indoor activities, enjoying winter scenery. Suggested clothing: Warm clothing, thick jacket, hat, scarf, gloves.
Castle Island climatological average
Annual average temperature: approx. 12°C / Annual rainfall: approx. 1070 mm / Summer humidity: 65%–75% / Rainiest month: March
Castle Island monthly average temperature and precipitation
Month
Air temperature (°C)
Precipitation (mm)
January
0.5°C
128.7
February
1.4°C
56.3
March
5.2°C
137
April
9.9°C
71
May
15.6°C
71
June
20.1°C
83
July
24.6°C
105.7
August
23°C
98.7
September
19°C
65
October
14.1°C
56
November
8.3°C
67.7
December
3.3°C
130
Castle Island weather for the next seven days
12/15
Monday
Sunny
-1°C/-10°C
12/16
Tuesday
Sunny
0.6°C/-7.9°C
12/17
Wednesday
Cloudy
4.4°C/-3.1°C
12/18
Thursday
Partly Cloudy
4.1°C/-0.7°C
12/19
Friday
Moderate rain
14.3°C/-2.1°C
12/20
Saturday
Sunny
0.5°C/-4.2°C
12/21
Sunday
Partly Cloudy
6.8°C/-0.6°C
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