São Luís
Brazil
Long-term weather forecast
Long-term weather forecast

August weather forecast and climate
São Luís, Brazil

August, the last month of the winter, in São Luís, is another tropical month, with average temperature varying between 30.7°C (87.3°F) and 23°C (73.4°F).
The ideal sea water temperature of 27.8°C (82°F) and only 4 rainfall days, with 29.4mm (1.2") of accumulated rainfall, make August the best time for swimming and other water activities.

Temperature

In August, the average high-temperature in São Luís, Brazil, is essentially the same as in July - a still tropical 30.7°C (87.3°F). In São Luís, in August, the average low-temperature is 23°C (73.4°F).

Heat index

In August, the average heat index is estimated at a blistering 41.3°C (106.3°F). Beware - heat cramps and heat exhaustion are very likely. Heatstroke is imminent with prolonged activity.
Note that heat index values are valued for light wind and location in the shade. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature', 'felt air temperature', 'real feel', or 'feels like', is a measure that combines both air temperature and relative humidity into a single value that indicates how hot the weather feels. Additional factors like activity, metabolic differences, clothing, and differences in body mass, height, and shape affect individual temperature impact. 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. Under high air temperature and humidity (high heat index) conditions, perspiration is limited, and the perception of heat is increased. 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

In August, the average relative humidity is 84%.

Rainfall

In São Luís, in August, it is raining for 4 days, with typically 29.4mm (1.2") of accumulated precipitation. In São Luís, during the entire year, the rain falls for 130 days and collects up to 2290.2mm (90.2") of precipitation.

Sea temperature

In São Luís, the average seawater temperature is 27.8°C (82°F).
Note: Water temperature between 25°C (77°F) and 29°C (84.2°F) is regarded as very warm and enjoyable by all. With these temperatures, water activities are pleasurable, without feeling uncomfortable for prolonged periods.

Daylight

May through August, with an average of 12h of daylight, are months with the shortest days.

Sunshine

With an average of 8.4h of sunshine, August has the most sunshine of the year in São Luís.

UV index

In August, the average daily maximum UV index is 11. A UV Index reading of 11, and higher, represents an excessive health risk from the exposure to the Sun's UV radiation for ordinary individuals.
Note: In August, the average maximum UV index of 11 translate into the following recommendations:
Take all required precautions, as unprotected skin and eyes can burn in minutes. 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. A broad-spectrum sunscreen of SPF 30+ should be liberally applied and re-applied every two hours, and immediately after an outdoor workout or a swim. Caution! The reflection of sand and water significantly increases the intensity of the Sun's UV radiation.

What is the temperature in August in São Luís?

In São Luís, Brazil, in August, the average high-temperature is 30.7°C (87.3°F), and the average low-temperature is 23°C (73.4°F). The average heat index (a.k.a. 'felt air temperature', 'feels like'), that represents influence of the relative humidity to air temperaure, in August is appraised at 41.3°C (106.3°F).

What is the average humidity in August in São Luís?

In São Luís, the average relative humidity in August is 84%.

How much does it rain in São Luís in August?

In São Luís, Brazil, in August, during 4 rainfall days, 29.4mm (1.2") of precipitation is typically accumulated.

How warm is the water in August in São Luís?

In August, the average sea temperature in São Luís is 27.8°C (82°F). For any water activity, surface water temperatures between 25°C (77°F) and 29°C (84.2°F) are considered as excellent and extremely pleasant for lengthened periods.

What is the month with the shortest days in São Luís?

Months with the shortest days in São Luís are May through August, with an average of 12h of daylight.

How many hours of daylight does São Luís have in August?

In August, the average length of the day in São Luís, Brazil, is 12h.

What month has the most sunshine in São Luís?

August has the most sunshine of the year, with an average of 8.4h of sunshine.

How long on average sun shines in August in São Luís?

The average sunshine in August is 8.4h.

What is the UV index intensity in August in São Luís?

In São Luís, the average daily maximum UV index in August is 11. A UV Index of 11, and more, symbolizes an extreme health vulnerability from the exposure to the Sun's UV rays.
Average temperature in August - São Luís, Brazil
  • Average high temperature in August: 30.7°C

The warmest month (with the highest average high temperature) is November (31.4°C).
Months with the lowest average high temperature are February and March (29.4°C).

  • Average low temperature in August: 23°C

Months with the highest average low temperature are November and December (24°C).
The coldest month (with the lowest average low temperature) is July (22.6°C).

Average humidity in August - São Luís, Brazil
  • Average humidity in August: 84%

The month with the highest relative humidity is April (90%).
The month with the lowest relative humidity is December (71%).

Average rainfall in August - São Luís, Brazil
  • Average rainfall in August: 29.4mm

The wettest month (with the highest rainfall) is April (475.9mm).
The driest month (with the lowest rainfall) is October (7.6mm).

Average rainfall days in August - São Luís, Brazil
  • Average rainfall days in August: 4 days

The month with the highest number of rainy days is March (23 days).
Months with the lowest number of rainy days are October and November (1 days).

Average sea temperature in August - São Luís, Brazil
  • Average sea temperature in August: 27.8°C

The best month for swimming (with the highest average sea temperature) is March (28.9°C).
The coldest month (with the lowest average sea temperature) is September (27.3°C).

Average daylight in August / Average sunshine in August - São Luís, Brazil
  • Average daylight in August: 12h

Months with the longest days are January and December (Average daylight: 12.3h).
Months with shortest days are May, June, July and August (Average daylight: 12h).

  • Average sunshine in August: 8.4h

The month with most sunshine is August (Average sunshine: 8.4h).
The month with least sunshine is March (Average sunshine: 3.5h).

Average UV index in August - São Luís, Brazil
  • Average UV index in August: 11

Months with the highest UV index are January, February, March, April, September, October, November and December (UV index 12).
Months with the lowest UV index are June and July (UV index 10).