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

October weather forecast and climate
São Luís, Brazil

October, like September, is another hot spring month in São Luís, Brazil, with temperature in the range of an average low of 23.7°C (74.7°F) and an average high of 31.2°C (88.2°F).
The ideal sea water temperature of 27.5°C (81.5°F) and only 1 rainfall days, with 7.6mm (0.3") of accumulated rainfall, make October the best time for swimming and other water activities.

Temperature

In October, the average high-temperature in São Luís, Brazil, is relatively the same as in September - a still hot 31.2°C (88.2°F). In October, in São Luís, the average low-temperature is 23.7°C (74.7°F).

Heat index

In October, the average heat index is estimated at a scorching 41.9°C (107.4°F). Be wary - heat exhaustion and heat cramps are highly anticipated. With continued activity, heatstroke is very likely.
Take into consideration that the heat index values are calculated for shade and light wind conditions. With the 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 an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. This effect is individual, with diverse people perceiving weather differently for numerous reasons (pregnancy, differences in body mass, height, and shape, wind), and activity. Be aware that direct exposure to sunlight increases heat impact, and may raise the heat index additionally, 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. 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

In October, the average relative humidity is 81%.

Rainfall

The month with the least rainfall is October when the rain falls for 1 days and typically collects 7.6mm (0.3") of precipitation.

Sea temperature

In São Luís, the average water temperature is 27.5°C (81.5°F).
Note: For swimming, diving, and other water activities, temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

Daylight

In São Luís, Brazil, the average length of the day in October is 12.2h.

Sunshine

In October, the average sunshine is 8.1h.

UV index

January through April, September through December, with an average maximum UV index of 12, are months with the highest UV index in São Luís. A UV Index of 11, and more, symbolizes an ultimate health vulnerability from the exposure to the Sun's UV rays for the average person.
Note: In October, the average maximum UV index of 12 translate into the following recommendations:
Practice all essential precautions. Protection against sun damage is crucial. 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 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. 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. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.

What is the temperature in October in São Luís?

The average high-temperature, in October, in São Luís, Brazil, is 31.2°C (88.2°F), while the average low-temperature is 23.7°C (74.7°F). In October, the average heat index (a.k.a. 'felt air temperature', 'apparent temperature'), that represents influence of the relative humidity to air temperaure, is estimated at 41.9°C (107.4°F).

What is the average humidity in October in São Luís?

The average relative humidity in October in São Luís is 81%.

How many days does it rain in October in São Luís?

In São Luís, during October, the rain falls for 1 days and regularly aggregates up to 7.6mm (0.3") of precipitation.

What is the driest month in São Luís?

The month with the least rainfall is October when the rain falls for 1 days and typically collects 7.6mm (0.3") of precipitation.

How warm is the water in October in São Luís?

In São Luís, Brazil, the average seawater temperature in October is 27.5°C (81.5°F). For swimming, diving, and other water activities, temperatures between 25°C (77°F) and 29°C (84.2°F) are perceived as very enjoyable and pleasurable for prolonged periods without feeling uncomfortable.

What is the average length of the day in October in São Luís?

In October, the average length of the day is 12.2h.

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

In October, the average sunshine in São Luís is 8.1h.

What are the months with the highest UV index in São Luís?

Months with the highest UV index in São Luís are January through April, September through December, with an average maximum UV index of 12.

What is the UV index reading in October in São Luís?

In São Luís, Brazil, the average daily maximum UV index in October is 12. A UV Index of 11, and more, symbolizes an extreme health vulnerability from the exposure to the Sun's UV radiation.
Average temperature in October - São Luís, Brazil
  • Average high temperature in October: 31.2°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 October: 23.7°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 October - São Luís, Brazil
  • Average humidity in October: 81%

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

Average rainfall in October - São Luís, Brazil
  • Average rainfall in October: 7.6mm

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 October - São Luís, Brazil
  • Average rainfall days in October: 1 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 October - São Luís, Brazil
  • Average sea temperature in October: 27.5°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 October / Average sunshine in October - São Luís, Brazil
  • Average daylight in October: 12.2h

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 October: 8.1h

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 October - São Luís, Brazil
  • Average UV index in October: 12

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).