December weather forecast and climate
Castilla, Costa Rica

Weather in December

The first month of the winter, December, is also a moderately hot month in Castilla, Costa Rica, with average temperature fluctuating between 29.5°C (85.1°F) and 22.2°C (72°F).

Temperature

In Castilla, the average high-temperature in December is practically the same as in November - a still warm 29.5°C (85.1°F). The average low-temperature, in Castilla, is 22.2°C (72°F).

Heat index

In December, the average heat index is evaluated at a torrid 35.7°C (96.3°F). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Note that heat index values are valued for light wind and location in the shade. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel', 'felt air temperature', 'feels like', or 'apparent temperature', is a measure that combines both air temperature and relative humidity into a single value that indicates how hot the weather feels. Additional factors like activity, wind, clothing, and differences in body mass, height, and shape affect individual temperature impact. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.
The human body normally cools itself by perspiration, as evaporated sweat carries heat away from the body. Under high air temperature and humidity (high heat index) conditions, perspiration is limited, and the perception of heat is increased. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

In December, the average relative humidity is 78%.

Rainfall

In Castilla, during December, the rain falls for 5.7 days and regularly aggregates up to 9mm (0.35") of precipitation. Throughout the year, in Castilla, Costa Rica, there are 188.5 rainfall days, and 1202mm (47.32") of precipitation is accumulated.

Daylight

December has the shortest days of the year, with an average of 11.5h of daylight.

Sunshine

In December, the average sunshine in Castilla is 9.6h.

UV index

January through October and December, with an average maximum UV index of 7, are months with the highest UV index in Castilla. A UV Index value of 6 to 7 symbolizes a high threat to health from the exposure to the Sun's UV rays for ordinary individuals.
Note: The average daily UV index of 7 transform into the following instructions:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. A wide-brim hat offers excellent sun protection for eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
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FAQ

What is the temperature in December in Castilla?

In Castilla, in December, the average high-temperature is 29.5°C (85.1°F), and the average low-temperature is 22.2°C (72°F). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), that represents influence of the relative humidity to air temperaure, in December is evaluated at 35.7°C (96.3°F).

What is the average humidity in December in Castilla?

The average relative humidity in December in Castilla is 78%.

How much does it rain in Castilla in December?

In Castilla, Costa Rica, in December, it is raining for 5.7 days, with typically 9mm (0.35") of accumulated precipitation.

What is the month with the shortest days in Castilla?

With an average of 11.5h of daylight, December has the shortest days of the year in Castilla.

What is the average length of the day in December in Castilla?

In Castilla, the average length of the day in December is 11.5h.

How long on average sun shines in December in Castilla?

The average sunshine in December in Castilla is 9.6h.

When is the highest UV index in Castilla?

Months with the highest UV index in Castilla, Costa Rica, are January through October and December, with an average maximum UV index of 7.

What is the UV index reading in December in Castilla?

The average daily maximum UV index in December is 7. A UV Index of 6 to 7 symbolizes a high hazard to health from unsafe exposure to the Sun's UV rays.

Average temperature in December
Castilla, Costa Rica

Average temperature in December - Castilla, Costa Rica
  • Average high temperature in December: 29.5°C

The warmest month (with the highest average high temperature) is April (34.9°C).
The month with the lowest average high temperature is October (29°C).

  • Average low temperature in December: 22.2°C

The month with the highest average low temperature is May (24.8°C).
The coldest month (with the lowest average low temperature) is January (22°C).

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Average pressure in December
Castilla, Costa Rica

Average pressure in December - Castilla, Costa Rica
  • Average pressure in December: 1010.7mbar

The month with the highest atmospheric pressure is January (1011.3mbar).
The month with the lowest atmospheric pressure is October (1010.1mbar).

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Average wind speed in December
Castilla, Costa Rica

Average wind speed in December - Castilla, Costa Rica
  • Average wind speed in December: 16.4km/h

The windiest month (with the highest average wind speed) is February (21.4km/h).
The calmest month (with the lowest average wind speed) is September (6.8km/h).

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Average humidity in December
Castilla, Costa Rica

Average humidity in December - Castilla, Costa Rica
  • Average humidity in December: 78%

The month with the highest relative humidity is October (87%).
The month with the lowest relative humidity is April (62%).

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Average rainfall in December
Castilla, Costa Rica

Average rainfall in December - Castilla, Costa Rica
  • Average rainfall in December: 9mm

The wettest month (with the highest rainfall) is October (274mm).
The driest month (with the least rainfall) is March (1mm).

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Average rainfall days in December
Castilla, Costa Rica

Average rainfall days in December - Castilla, Costa Rica
  • Average rainfall days in December: 5.7 days

The month with the highest number of rainy days is September (27.7 days).
The month with the least rainy days is February (2 days).

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Average daylight in December /
Average sunshine in December
Castilla, Costa Rica

Average daylight in December / Average sunshine in December - Castilla, Costa Rica
  • Average daylight in December: 11.5h

Months with the longest days are June and July (Average daylight: 12.7h).
The month with the shortest days is December (Average daylight: 11.5h).

  • Average sunshine in December: 9.6h

The month with the most sunshine is July (Average sunshine: 10.2h).
Months with the least sunshine are January and October (Average sunshine: 7.6).

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Average sunshine days in December
Castilla, Costa Rica

Average sunshine days in December - Castilla, Costa Rica
  • Average sunshine days in December: 24.3 days

The month with the most sunshine days is March (28.8 days).
The month with the least sunshine days is September (1.1 days).

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Average UV index in December
Castilla, Costa Rica

Average UV index in December - Castilla, Costa Rica
  • Average UV index in December: 7

Months with the highest UV index are January, February, March, April, May, June, July, August, September, October and December (UV index 7).
The month with the lowest UV index is November (UV index 6).

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Average cloud cover in December
Castilla, Costa Rica

Average cloud cover in December - Castilla, Costa Rica
  • Average cloud cover in December: 18

The month with the most cloud cover is October (Cloud cover 46).
The month with the least cloud cover is February (Cloud cover 10).

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Average visibility in December
Castilla, Costa Rica

Average visibility in December - Castilla, Costa Rica
  • Average visibility in December: 10km

Months with the highest visibility are January, February, March, April, May and December (10km).
Months with the lowest visibility are September and October (8km).

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