This report describes the typical weather at the El Salvador International Airport (San Salvador, El Salvador) weather station over the course of an average January. It is based on the historical records from 1996 to 2012. Earlier records are either unavailable or unreliable.
San Salvador has a tropical savanna climate with dry winters. The area within 25 mi of this station is covered by oceans and seas (38%), forests (29%), croplands (24%), and grasslands (5%).
The month of January is characterized by essentially constant daily high temperatures, with daily highs around 92°F throughout the month, exceeding 95°F or dropping below 88°F only one day in ten.
Over the course of January, the length of the day is essentially constant. The shortest day of the month is January 3 with 11:21 hours of daylight; the longest day is January 31 with 11:33 hours of daylight.
The earliest sunrise is at 6:19am on January 1; the latest sunset is at 5:56pm on January 31; the latest sunrise is at 6:24am on January 25; the earliest sunset is at 5:40pm on January 1.
Daylight saving time (DST) is not observed in 2012.
The median cloud cover is 43% (partly cloudy) and does not vary substantially over the course of the month.
On January 16, a representative day, the sky is clear or mostly clear 18% of the time, partly cloudy 7% of the time, and mostly cloudy or overcast 5% of the time.
The average probability that some form of precipitation will be observed in a given day is 2%, with little variation over the course of the month.
Throughout January, the most common forms of precipitation are drizzle, light rain, moderate rain, and thunderstorms.
Drizzle is the most severe precipitation observed during 37% of those days with precipitation. It is most likely around January 26, when it is observed during 1% of all days.
Light rain is the most severe precipitation observed during 25% of those days with precipitation. It is most likely around January 27, when it is observed during 1% of all days.
Moderate rain is the most severe precipitation observed during 23% of those days with precipitation. It is most likely around January 11, when it is observed during 1% of all days.
Thunderstorms are the most severe precipitation observed during 13% of those days with precipitation. They are most likely around January 1, when it is observed during 0% of all days.
Either snow is exceptionally unlikely to fall at this location in January or this station does not reliably report precipitation types.
The relative humidity typically ranges from 37% (comfortable) to 89% (very humid) over the course of a typical January, rarely dropping below 27% (dry) and reaching as high as 100% (very humid).
The air is driest around January 30, at which time the relative humidity drops below 43% (comfortable) three days out of four; it is most humid around January 30, rising above 84% (humid) three days out of four.
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a typical January, the dew point typically varies from 59°F (comfortable) to 69°F (muggy) and is rarely below 53°F (very comfortable) or above 74°F (very muggy).
Over the course of January typical wind speeds vary from 0 mph to 12 mph (calm to moderate breeze), rarely exceeding 20 mph (fresh breeze).
The highest average wind speed of 7 mph (light breeze) occurs around January 9, at which time the average daily maximum wind speed is 12 mph (moderate breeze).
The lowest average wind speed of 6 mph (light breeze) occurs around January 31, at which time the average daily maximum wind speed is 12 mph (gentle breeze).