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

San Salvador, welcoming December, observes an average high-temperature of a still warm 29.9°C (85.8°F), remaining consistent with the preceding month. San Salvador's temperature lowers to a mean of 19.5°C (67.1°F) during the nights in December.

Heat index

The heat index value during December is appraised at a sweltering 35°C (95°F). Undertake extra safety actions, heat cramps and heat exhaustion are expected. Heatstroke may result from lengthy activity.
Take note of the fact that heat index values are based on shaded circumstances with light airflows. Heat index values have the potential to be boosted by 15 Fahrenheit (8 Celsius) degrees due to direct sunlight.
Note: The heat index, also known as 'feels like' or 'felt air temperature', is derived by integrating air temperature with the existing relative humidity to express the perceived warmth. The influence of weather can be personal, changing with an individual's body mass, height, and level of physical exertion. Be mindful that being in direct sunlight might mean feeling hotter, with the heat index rising by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values remain especially vital for babies and toddlers. Kids often lack the knowledge about the necessity to take breaks and consume liquids. Thirst, as a late symptom of dehydration, necessitates the maintenance of hydration, particularly during enduring physical activities.
To cool down, the human body relies on perspiration, a process where excessive heat is eliminated as sweat evaporates. Under high air temperature and humidity (high heat index) conditions, perspiration is limited, and the perception of heat is increased. With body temperatures on the rise, inefficient heat shedding can lead to dehydration and its associated complications.

Humidity

In San Salvador, the average relative humidity in December is 70%.

Rainfall

In San Salvador, during December, the rain falls for 2.3 days and regularly aggregates up to 4mm (0.16") of precipitation. Throughout the year, there are 187 rainfall days, and 1106mm (43.54") of precipitation is accumulated.

Daylight

The month with the shortest days is December, with an average of 11h and 18min of daylight.
On the first day of the month, sunrise is at 06:04 and sunset at 17:27. On the last day of December, 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 threat to health from unprotected exposure to Sun's UV rays for the average person.
Note: During December, 6 as the daily maximum UV index converts into the following advice:
Persist with precautions and heed sun safety advice. Prevention of sunburn is compulsory. Minimize exposure to direct sunlight and seek shade from 10 a.m. to 4 p.m., when UV radiation is most intense, but remember that shade structures may not offer complete protection. Employ a wide-brim hat for potent defense against up to 50% of UV rays.