May weather forecast
Santo Tomás, El Salvador

The last month of the spring, May, is another tropical month in Santo Tomás, El Salvador, with an average temperature fluctuating between 22.6°C (72.7°F) and 31.8°C (89.2°F).

Temperature

The start of May marks an average high-temperature of a still hot 31.8°C (89.2°F), hardly distinguishable from the conditions in April. Throughout May, the average low-temperature in Santo Tomás dips to an agreeable 22.6°C (72.7°F).

Heat index

May's average heat index is estimated at a scorching 42°C (107.6°F). Adopt special protective actions against heat exhaustion and heat cramps. Long-duration activity risks heatstroke.
Consider that heat index readings are for situations in the shade and light wind. The heat index may experience an enhancement of 15 Fahrenheit (8 Celsius) degrees under direct sunlight.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', reflects the blend of air temperature and relative humidity to give a temperature impression. The impact of temperature is individual, as people's perception of weather may change based on their body mass, height, and physical activity. Keep in mind that direct sunshine exposure can amplify the weather's effects, possibly increasing the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Young individuals usually face more risks than adults due to their lower sweat production. Their large skin surface area relative to their tiny bodies and high heat production from their activities adds to their risk.
The human body normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. With an abundance of moisture present in the air, the process of evaporation becomes less effective, and the body fails to cool down as it should, leading to the sensation of overheating. When heat uptake goes beyond the body's cooling mechanisms, there's a surge in body temperature, posing health risks.

Humidity

The average relative humidity in May in Santo Tomás, El Salvador, is 76%.

Rainfall

The month with the most rainfall in Santo Tomás is May, when the rain falls for 26.9 days and typically aggregates up to 267mm (10.51") of precipitation.

Daylight

The average length of the day in May is 12h and 46min.
On the first day of May, sunrise is at 05:34 and sunset at 18:12. On the last day of the month, sunrise is at 05:28 and sunset at 18:20 CST.

Sunshine

In Santo Tomás, El Salvador, the average sunshine in May is 10.7h.

UV index

The months with the lowest UV index in Santo Tomás are May through December, with an average maximum UV index of 6. A UV Index estimate of 6 to 7 represents a high threat to health from exposure to the Sun's UV radiation for the ordinary person.
Note: The maximum daily UV index, 6 in May, converts into the following recommendations:
Take precautions and adopt sun safety practices. Protection against sunburn is obliged. 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. Using UVA and UVB-protective sunglasses and sun-protective clothing is effective against UV radiation.