September weather forecast
San Salvador, El Salvador

September, the first month of the autumn in San Salvador, is also a moderately hot month, with an average temperature varying between 29.8°C (85.6°F) and 21.5°C (70.7°F).

Temperature

In September, the average high-temperature is almost the same as in August - a warm 29.8°C (85.6°F). The average low-temperature, in September, is 21.5°C (70.7°F).

Heat index

In September, the average heat index is evaluated at a very hot 37.6°C (99.7°F). Take extra precautions, as heat cramps and heat exhaustion are possible. Sustained activity may result in heatstroke.
Note that heat index values are valued for light wind and location in the shade. With exposure to direct sunlight, the heat index may be increased by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'apparent temperature', 'real feel', or 'feels like', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. Additional factors like clothing, differences in body mass, height, and shape, pregnancy, and activity influence one's weather impression. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Young children are generally more endangered than adults, as they usually less sweat. And also, due to larger skin surface relative to their small bodies and higher heat production as a result of their activity.
The human body cools itself through perspiration, as excessive warmth is removed from the body through sweat evaporation. With a lot of moisture in the air, the evaporation process is not as effective, and the body does not cool down as efficiently, creating a perception of overheating. If the body can not disperse the excessive heat and body temperature reaches conditions of hyperthermia, above 37.5°C (99.5°F) to 38.3°C (100.9°F), thermal conditions are potentially life-threatening.

Humidity

September and October, with an average relative humidity of 82%, are the most humid months in San Salvador.

Rainfall

In San Salvador, it is raining for 26.3 days, with typically 142mm (5.59") of accumulated precipitation. In San Salvador, during the entire year, the rain falls for 187 days and collects up to 1106mm (43.54") of precipitation.

Daylight

In September, the average length of the day in San Salvador is 12h and 12min.
On the first day of the month, sunrise is at 05:45 and sunset at 18:08. On the last day of September, sunrise is at 05:46 and sunset at 17:47 CST.

Sunshine

In San Salvador, the average sunshine in September is 9.3h.

UV index

January, May, June, August through December, with an average maximum UV index of 6, are months with the lowest UV index in San Salvador. A UV Index reading of 6 to 7 represents a high health vulnerability from unsafe exposure to UV radiation for average individuals.
Note: The daily maximum UV index of 6 in September interpret into the following advice:
Take precautions against overexposure. Protection against sun damage is needed. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.