San Salvador, the capital of El Salvador, sits in a valley of the Central American volcanic chain at around 660 metres above sea level, overlooked by the San Salvador volcano at approximately 13.69°N, 89.19°W. Its altitude tempers the tropical latitude to give a tropical savanna climate (Köppen Aw) — warm year-round — with a sharply defined wet and dry season.

There is no summer in the temperate sense: temperatures stay warm and steady, with daytime highs around 30–32°C and mild nights near 18–19°C, moderated by the valley's elevation. The rainy season, from May to October — the local 'invierno' — brings warm, bright mornings that cloud over into heavy afternoon and evening downpours and thunderstorms.

There is no true winter, but the dry season from November to April brings warm, sunny, breezy days with almost no rain and lower humidity, cooled by the northeasterly trade winds. Nights are pleasantly mild; this bright, dry stretch is comfortably the most pleasant time of year in the volcanic valley.

San Salvador receives on the order of 1,700–1,800 mm of rain a year, overwhelmingly concentrated in the rainy season from May to October, with peaks in June and September, while December to March is markedly dry. Live rainfall, humidity, and pressure readings for the city are shown in the panels above.

San Salvador sits on the slopes of an active volcano in a country wedged between two oceans, and its rainy season brings a compound danger: torrential downpours — sometimes from Pacific storms or the remnants of Caribbean hurricanes crossing the isthmus — saturate the steep volcanic soils and trigger deadly landslides.

To follow any single measurement in San Salvador more closely, use our live instruments: the online barometer for atmospheric pressure, the thermometer for temperature, the hygrometer for humidity, the anemometer for wind speed, the wind vane for wind direction, and the rain gauge for rainfall.