December weather forecast
San Salvador, El Salvador

December in San Salvador brings a definitive end to the rainy season. The slightly cooler temperatures, coupled with increased wind speeds, make for a more refreshing end to the year. Although daylight hours continue to decrease, clear skies and improved visibility dominate the landscape. The month is marked by scant rainfalls of only 4mm (0.16"), spread over a mere 2.3 days. This severe reduction indicates the city's shift to its dry season and sets the stage for the weather cycle to repeat in the coming new year.

Temperature

December's arrival is characterized by an average high-temperature of a still moderately hot 29.9°C (85.8°F), identical to that of November. December's nights in San Salvador observe an average temperature of 19.5°C (67.1°F).

Heat index

Throughout December, the heat index is calculated to be a torrid 35°C (95°F). Ensure additional precautions, heat exhaustion and heat cramps may be expected. Heatstroke could occur from sustained activity.
Heat index data is primarily for areas with shade and subjected to light winds. A rise in the heat index by 15 Fahrenheit (8 Celsius) degrees may result from direct sunlight exposure.
Note: The heat index, also known as 'real feel' or 'felt air temperature', quantifies the warmth felt when relative humidity is considered. The impact of weather on an individual can be subjective, affected by the person's activity and heat perception, which can vary due to elements including wind, clothing, and metabolic differences. Exposure to direct sun rays can influence the heat you feel, pushing the heat index up by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely significant for children. Children often overlook the necessity for resting and fluid replenishment. Thirst is a late sign of dehydration - thus, it is critical to stay hydrated, especially during extended periods of physical activities.
The body's self-cooling mechanism is rooted in perspiration, where evaporating sweat cools down excessive warmth. When the level of relative humidity is elevated, evaporation diminishes, causing more warmth to be retained in the body than in dry air. Accumulating more heat than the body can dissipate leads to an uptick in body temperature, with potential heat stress consequences.

Humidity

The average relative humidity in December is 70%.

Rainfall

In San Salvador, in December, during 2.3 rainfall days, 4mm (0.16") of precipitation is typically accumulated. In San Salvador, during the entire year, the rain falls for 187 days and collects up to 1106mm (43.54") of precipitation.

Daylight

December has the shortest days of the year, with an average of 11h and 18min of daylight.
On the first day of December, sunrise is at 06:04 and sunset at 17:27. On the last day of the month, sunrise is at 06:20 and sunset at 17:40 CST.

Sunshine

The months with the least sunshine are January and December, with an average of 7.7h of sunshine.

UV index

January, May, June, August through December, with an average maximum UV index of 6, are months with the lowest UV index. A UV Index reading of 6 to 7 represents a high health hazard from exposure to the Sun's UV rays for the average person.
Note: The maximum daily UV index of 6 in December interprets into the following recommendations:
Guard against overexposure. Protection from sun-induced harm is essential. Avoid direct sunlight between the hours of 10 a.m. and 4 p.m., when UV radiation is at its peak. Keep in mind that shade structures may not provide complete protection. Tightly woven clothing, when worn loosely, shields effectively against the Sun.