May weather forecast
Boa Vista, Brazil

May, the last month of the spring in Boa Vista, is another tropical month, with an average temperature ranging between min 23.4°C (74.1°F) and max 30.8°C (87.4°F).

Temperature

In Boa Vista, the average high-temperature in May is essentially the same as in April - a still hot 30.8°C (87.4°F). In May, the average low-temperature is 23.4°C (74.1°F).

Heat index

The average heat index in May is computed to be an extremely hot 40°C (104°F). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like', 'felt air temperature', 'apparent temperature', or 'real feel', combines air temperature and relative humidity to represent a human perceived temperature equivalent. This effect is individual, with diverse people perceiving weather differently for numerous reasons (pregnancy, clothing, differences in body mass, height, and shape), and activity. 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 particularly important for children. 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 normally cools itself by perspiration. Excessive warmth is eliminated from the body by evaporation of sweat. A higher relative humidity affects normal body cooling by reducing the evaporation rate, subsequently lowering the rate at which the body cools and increasing the perception of heat. When heat gain exceeds the level the body can remove, body temperature begins to rise, and heat-related illnesses and disorders may develop.

Humidity

In May, the average relative humidity is 80%.

Rainfall

In Boa Vista, during May, the rain falls for 26.9 days and regularly aggregates up to 215mm (8.46") of precipitation. In Boa Vista, during the entire year, the rain falls for 241.8 days and collects up to 1216mm (47.87") of precipitation.

Daylight

In May, the average length of the day is 12h and 15min.
On the first day of the month, sunrise is at 05:53 and sunset at 18:06. On the last day of May, in Boa Vista, sunrise is at 05:52 and sunset at 18:08 -04.

Sunshine

In Boa Vista, the average sunshine in May is 8.5h.

UV index

The months with the highest UV index are January through May, July through December, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high threat to health from unsafe exposure to UV radiation for the ordinary person.
Note: In May, the average maximum UV index of 7 translate 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. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.