El Salvador's tropical climate has pronounced wet and dry seasons. The dry season, *quot;verano" or summer, from December to April is dusty, especially in rural areas. The hottest months of the year, March and April, immediately precede the rainy season, "invierno" (winter). During the May-November rainy season, mornings are usually clear, with heavy rains in early evening and at night. Thunder and strong winds occasionally accompany the rain, and some June and September mornings are overcast. Occasional 2- to 3-day rainy spells occur. The average annual rainfall is 66 inches.
The three geographic zones have distinct climatic characteristics. The narrow coastal belt is a hot tropical savanna with lush vegetation and temperatures that average 80°F. The central highlands, where San Salvador lies, are slightly cooler, with an average temperature of 73°F. San Salvadorâ€™s temperatures range from 50°F to 90°F throughout the year. Incoming polar air infrequently causes cold nights and even frost. The highlands in the extreme north of El Salvador are consistently cool.
Earthquakes and volcanic eruptions have littered El Salvadorâ€™s history. Earthquakes ranging from 6.5 to 7.9 on the Richter Scale have struck the country at least 15 times since 1700. The most serious recent earthquakes occurred on January 13 and February 13, 2001. Although damage in San Salvador was slight, schools, hospitals, businesses, and public buildings throughout the country were damaged or destroyed. These two powerful quakes resulted in 1,300 deaths and left more than one million homeless. Infrastructure damages are estimated at $1.6 billion, or 12% of the country's GDP.
Of the volcanoes located within the metropolitan area of San Salvador, Volcano San Salvador erupted last in 1917 and Volcano Ilopango in 1879.
Although hurricanes do not usually threaten El Salvador directly, strong Caribbean storms can generate heavy winds and rains. Hurricane Mitch hit El Salvador in November 1998, generating extreme rainfall which caused widespread flooding.