Average Weather in San Salvador El Salvador
In San Salvador, the wet season is oppressive and overcast, the dry season is humid and mostly clear, and it is warm year round. Over the course of the year, the temperature typically varies from 64°F to 85°F and is rarely below 60°F or above 88°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
In San Salvador, the average percentage of the sky covered by clouds experiences extreme seasonal variation over the course of the year.
The clearer part of the year in San Salvador begins around November 15 and lasts for 5.0 months, ending around April 16. On January 10, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 79% of the time, and overcast or mostly cloudy 21% of the time.
The cloudier part of the year begins around April 16 and lasts for 7.0 months, ending around November 15. On June 5, the cloudiest day of the year, the sky is overcast or mostly cloudy 93% of the time, and clear, mostly clear, or partly cloudy 7% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in San Salvador varies significantly throughout the year.
The wetter season lasts 5.3 months, from May 15 to October 25, with a greater than 25% chance of a given day being a wet day. The chance of a wet day peaks at 48% on September 12.
The drier season lasts 6.7 months, from October 25 to May 15. The smallest chance of a wet day is 1% on February 28.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 48% on September 12.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. San Salvador experiences extreme seasonal variation in monthly rainfall.
The rainy period of the year lasts for 7.4 months, from April 13 to November 26, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around September 20, with an average total accumulation of 5.8 inches.
The rainless period of the year lasts for 4.6 months, from November 26 to April 13. The least rain falls around February 15, with an average total accumulation of 0.1 inches.
Average Monthly Rainfall
The length of the day in San Salvador varies over the course of the year. In 2017, the shortest day is December 21, with 11 hours, 19 minutes of daylight; the longest day is June 20, with 12 hours, 56 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:28 AM on June 1, and the latest sunrise is 56 minutes later at 6:24 AM on January 23. The earliest sunset is at 5:25 PM on November 20, and the latest sunset is 1 hour, 3 minutes later at 6:28 PM on July 8.
Daylight saving time (DST) is not observed in San Salvador during 2017.
Sunrise & Sunset with Twilight
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
San Salvador experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 8.9 months, from March 14 to December 11, during which time the comfort level is muggy, oppressive, or miserable at least 34% of the time. The muggiest day of the year is September 18, with muggy conditions 99% of the time.
The least muggy day of the year is January 25, with muggy conditions 12% of the time.
Humidity Comfort Levels
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in San Salvador experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 5.3 months, from November 3 to April 11, with average wind speeds of more than 3.8 miles per hour. The windiest day of the year is January 13, with an average hourly wind speed of 5.0 miles per hour.
The calmer time of year lasts for 6.7 months, from April 11 to November 3. The calmest day of the year is August 20, with an average hourly wind speed of 2.7 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in San Salvador varies throughout the year.
The wind is most often from the south for 2.7 months, from April 5 to June 27 and for 2.0 months, from August 9 to October 10, with a peak percentage of 40% on June 4. The wind is most often from the east for 1.4 months, from June 27 to August 9, with a peak percentage of 39% on July 15. The wind is most often from the north for 5.8 months, from October 10 to April 5, with a peak percentage of 66% on January 1.
San Salvador is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.The average water temperature does not vary significantly over the course of the year, remaining within 2°F of 84°F throughout.
Average Water Temperature
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy experiences some seasonal variation over the course of the year.
The brighter period of the year lasts for 2.0 months, from February 13 to April 13, with an average daily incident shortwave energy per square meter above 6.4 kWh. The brightest day of the year is March 23, with an average of 6.9 kWh.
The darker period of the year lasts for 1.4 months, from May 15 to June 26, with an average daily incident shortwave energy per square meter below 5.0 kWh. The darkest day of the year is June 5, with an average of 4.5 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of San Salvador are 13.689 deg latitude, -89.187 deg longitude, and 2,333 ft elevation.
The topography within 2 miles of San Salvador contains very significant variations in elevation, with a maximum elevation change of 1,909 feet and an average elevation above sea level of 2,328 feet. Within 10 miles contains very significant variations in elevation (5,810 feet). Within 50 miles also contains extreme variations in elevation (8,940 feet).
The area within 2 miles of San Salvador is covered by artificial surfaces (31%), grassland (25%), cropland (25%), and trees (17%), within 10 miles by cropland (33%) and trees (32%), and within 50 miles by water (29%) and cropland (29%).
This report illustrates the typical weather in San Salvador, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 4 weather stations near enough to contribute to our estimation of the temperature and dew point in San Salvador.
For each station, the records are corrected for the elevation difference between that station and San Salvador according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at San Salvador is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between San Salvador and a given station.
The stations contributing to this reconstruction are: Aeropuerto Internacional El Salvador (53%, 31 kilometers, southeast); Santa Rosa De Copan (22%, 129 kilometers, north); La Aurora International Airport (13%, 176 kilometers, northwest); and San José Airport (13%, 180 kilometers, west).
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.