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

January weather forecast and climate
São Luís, Brazil

January, the same as December, in São Luís, Brazil, is another hot summer month, with average temperature varying between 23.5°C (74.3°F) and 30°C (86°F).

Temperature

In January, the average high-temperature is practically the same as in December - a still hot 30°C (86°F). In January, the average low-temperature is 23.5°C (74.3°F).

Heat index

The average heat index is calculated to a torrid 39.1°C (102.4°F). Take special precautions - heat exhaustion and heat cramps are expected. Heatstroke may occur with lengthy activity.
Note that heat index values are valued for light wind and location in the shade. 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 'real feel', 'apparent temperature', 'felt air temperature', or 'feels like', is what the temperature feels like to the human body when the air temperature is combined with the relative humidity. Additional factors like activity, wind, differences in body mass, height, and shape, and metabolic differences 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.
Perspiration is the human body's physiological response to high temperatures and is an attempt to lower body temperature through evaporation of sweat. High relative humidity reduces the evaporation rate, resulting in a lower heat removal rate from the body, causing the perception of being overheated. 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 January, the average relative humidity is 85%.

Rainfall

In São Luís, during 13 rainfall days, 244.2mm (9.6") of precipitation is typically accumulated. Throughout the year, in São Luís, there are 130 rainfall days, and 2290.2mm (90.2") of precipitation is accumulated.

Sea temperature

In January, the average sea temperature is 28.6°C (83.5°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

Months with the longest days in São Luís, Brazil, are January and December, with an average of 12.3h of daylight.

Sunshine

In São Luís, Brazil, the average sunshine in January is 4.9h.

UV index

January through April, September through December, with an average maximum UV index of 12, are months with the highest UV index. A UV Index value of 11, and more, symbolizes an ultimate health vulnerability from the exposure to the Sun's UV rays for the average person.
Note: The average daily UV index of 12 transform into the following instructions:
Take all necessary precautions, as unprotected skin can burn in minutes. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. 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. Even on cloudy days, a sunscreen with a minimum 30 sun protection factor should be generously applied and frequently re-applied, including after every swim or outdoor exercise. Beware! The strength of the UV rays is significantly increased by the reflection of the water and sand.

What is the temperature in January in São Luís?

The average high-temperature, in January, is 30°C (86°F), while the average low-temperature is 23.5°C (74.3°F). In January, the average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), that takes the relative humidity and factores it into the air temperature reading, is appraised at 39.1°C (102.4°F).

What is the average humidity in January in São Luís?

In January, the average relative humidity in São Luís is 85%.

How much does it rain in São Luís in January?

In São Luís, in January, it is raining for 13 days, with typically 244.2mm (9.6") of accumulated precipitation.

What is the water temperature in January in São Luís?

In São Luís, Brazil, in January, the average water temperature is 28.6°C (83.5°F). 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.

When are the longest days in São Luís?

January and December, with an average of 12.3h of daylight, are months with the longest days.

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

In January, the average length of the day in São Luís is 12.3h.

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

In January, the average sunshine in São Luís is 4.9h.

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

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

How high is the UV index in January in São Luís?

The average daily maximum UV index in January is 12. A UV Index of 11, and more, symbolizes an extreme health vulnerability from the exposure to the Sun's UV rays.
Average temperature in January - São Luís, Brazil
  • Average high temperature in January: 30°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 January: 23.5°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 January - São Luís, Brazil
  • Average humidity in January: 85%

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

Average rainfall in January - São Luís, Brazil
  • Average rainfall in January: 244.2mm

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 January - São Luís, Brazil
  • Average rainfall days in January: 13 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 January - São Luís, Brazil
  • Average sea temperature in January: 28.6°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 January / Average sunshine in January - São Luís, Brazil
  • Average daylight in January: 12.3h

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 January: 4.9h

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 January - São Luís, Brazil
  • Average UV index in January: 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).