September weather forecast
Santarém, Brazil

The first month of the spring, September, is still a tropical month in Santarém, Brazil, with temperature in the range of an average high of 34.3°C (93.7°F) and an average low of 25.5°C (77.9°F).

Temperature

Upon the beginning of September, Santarém's high-temperatures register at a still tropical 34.3°C (93.7°F), closely mirroring the preceding month. During September, the temperature tends to dip to an average of 25.5°C (77.9°F) at night.

Heat index

Throughout September, the heat index is evaluated at a blisteringly hot 44°C (111.2°F). Be alert: Heat exhaustion along with heat cramps are probable. Heatstroke is a threat with sustained physical activity.
In the scope of the heat index, its values resonate with shade and light wind conditions. With exposure to direct sunshine, the heat index could climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', gauges the sensation of temperature factoring in the air's moisture content. A person's impression of weather can be shaped by several aspects, among them metabolic variations, pregnancy, and levels of physical activity. Sunshine, when direct, has the potential to intensify weather effects, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Children frequently underestimate the importance of resting and drinking fluids. Thirst is a symptom of advanced dehydration - hence the need to hydrate regularly, especially during protracted physical exercises.
When temperatures rise, the human body turns to perspiration, using the cooling power of evaporating sweat. Under high air temperature and humidity (high heat index) conditions, perspiration is limited, and the perception of heat is increased. When heat uptake goes beyond the body's cooling mechanisms, there's a surge in body temperature, posing health risks.

Humidity

September is the least humid month in Santarém, Brazil, with an average relative humidity of 63%.

Rainfall

In Santarém, during September, the rain falls for 13.8 days and regularly aggregates up to 36mm (1.42") of precipitation. In Santarém, during the entire year, the rain falls for 259.2 days and collects up to 2234mm (87.95") of precipitation.

Daylight

In Santarém, the average length of the day in September is 12h and 6min.
On the first day of September in Santarém, sunrise is at 06:36 and sunset at 18:40. On the last day of the month, sunrise is at 06:24 and sunset at 18:32 -03.

Sunshine

With an average of 9.8h of sunshine, September has the most sunshine of the year.

UV index

January, April through December, with an average maximum UV index of 7, are months with the highest UV index in Santarém. A UV Index value of 6 to 7 symbolizes a high health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: The average daily UV index of 7 in September transforms into the following instructions:
Take precautions against overexposure. Protection against sun damage is needed. Limit your exposure to the sun's UV radiation, which is strongest between 10 a.m. and 4 p.m., and note that parasols or canopies may not provide full sun protection. Boost your sun resistance with garments that are densely woven yet spacious.