San Juan
Argentina
Long-term weather forecast
Long-term weather forecast

December weather forecast and climate
San Juan, Argentina

The first month of the summer, December, is still a tropical month in San Juan, Argentina, with temperature in the range of an average high of 34.3°C (93.7°F) and an average low of 18.3°C (64.9°F).

Temperature

In December, the average high-temperature is essentially the same as in November - a still hot 34.3°C (93.7°F). In December, in San Juan, the average low-temperature is 18.3°C (64.9°F).

Heat index

The average heat index in December is estimated at a sweltering 36.8°C (98.2°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'apparent temperature', 'real feel', or 'feels like', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. This effect is subjective, depending on the activity and individual's heat perception influenced by various reasons (clothing, wind, differences in body mass, height, and shape). 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. Excessive warmth is eliminated from the body by evaporation of sweat. With a lot of moisture in the air, the evaporation process is not as effective, and the body does not cool down as efficiently, creating a perception of overheating. 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 San Juan, the average relative humidity is 43%.

Rainfall

In San Juan, it is raining for 3 days, with typically 11.6mm (0.5") of accumulated precipitation. Throughout the year, in San Juan, there are 25.6 rainfall days, and 92.3mm (3.6") of precipitation is accumulated.

Daylight

December has the longest days of the year in San Juan, with an average of 14.2h of daylight.

Sunshine

December has the most sunshine of the year, with an average of 11.3h of sunshine.

What is the temperature in December in San Juan?

In San Juan, in December, the average high-temperature is 34.3°C (93.7°F), and the average low-temperature is 18.3°C (64.9°F). The average heat index (a.k.a. 'felt air temperature', 'real feel'), that combines relative humidity and air temperature, in December is evaluated at 36.8°C (98.2°F).

What is the average humidity in December in San Juan?

In San Juan, the average relative humidity in December is 43%.

How many days does it rain in December in San Juan?

In San Juan, Argentina, in December, it is raining for 3 days, with typically 11.6mm (0.5") of accumulated precipitation.

When are the longest days in San Juan?

With an average of 14.2h of daylight, December has the longest days of the year in San Juan.

What is the average length of the day in December in San Juan?

The average length of the day in December in San Juan, Argentina, is 14.2h.

What month has the most sunshine in San Juan?

December has the most sunshine of the year in San Juan, Argentina, with an average of 11.3h of sunshine.

How many hours of sunshine does San Juan have in December?

The average sunshine in December is 11.3h.
Average temperature in December - San Juan, Argentina
  • Average high temperature in December: 34.3°C

The warmest month (with the highest average high temperature) is January (34.6°C).
The month with the lowest average high temperature is July (16.3°C).

  • Average low temperature in December: 18.3°C

The month with the highest average low temperature is January (19.4°C).
Coldest months (with the lowest average low temperature) are June and July (1.1°C).

Average humidity in December - San Juan, Argentina
  • Average humidity in December: 43%

The month with the highest relative humidity is June (65%).
The month with the lowest relative humidity is November (41%).

Average rainfall in December - San Juan, Argentina
  • Average rainfall in December: 11.6mm

The wettest month (with the highest rainfall) is February (18.4mm).
The driest month (with the lowest rainfall) is June (1.3mm).

Average rainfall days in December - San Juan, Argentina
  • Average rainfall days in December: 3 days

Months with the highest number of rainy days are January and February (4 days).
The month with the lowest number of rainy days is June (0.6 days).

Average daylight in December / Average sunshine in December - San Juan, Argentina
  • Average daylight in December: 14.2h

The month with the longest days is December (Average daylight: 14.2h).
The month with shortest days is June (Average daylight: 10.1h).

  • Average sunshine in December: 11.3h

The month with most sunshine is December (Average sunshine: 11.3h).
The month with least sunshine is June (Average sunshine: 6.9h).