September weather forecast
São Caetano de Odivelas, Brazil

The first month of the spring, September, is also a hot month in São Caetano de Odivelas, Brazil, with an average temperature fluctuating between 24.5°C (76.1°F) and 31.1°C (88°F).

Temperature

September brings an average high-temperature of a still tropical 31.1°C (88°F), nearly identical to the preceding month. September nights experience a consistent temperature drop to a moderately hot 24.5°C (76.1°F).

Heat index

The heat index for September is evaluated at a blistering 41°C (105.8°F). Implement additional safety measures to avoid heat cramps and heat exhaustion. Persistent activity might trigger heatstroke.
It is worth noting that heat index values are gauged for conditions in the shade and light breezes. The heat index may scale up by 15 Fahrenheit (8 Celsius) degrees with direct sun exposure.
Note: The heat index, also known as 'felt air temperature' or 'feels like', is a calculated temperature value of how hot it feels when the moisture in the air is factored in. The influence of weather is personal, differing among individuals based on variations in body mass, stature, and the degree of physical exertion. You should know that direct sun exposure can heighten weather effects, potentially elevating the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Youngsters often neglect the necessity for rest and hydration. Thirst is a sign of advancing dehydration - thus the importance of maintaining hydration, specifically during long-lasting physical activities.
The body's inherent cooling system operates through perspiration, wherein evaporating sweat offsets excessive heat. Augmented relative humidity impedes typical body cooling mechanisms by lowering the evaporation rate, resulting in decreased body cooling and an amplified perception of heat. Rising body temperatures resulting from an imbalance in heat absorption can lead to potential thermal issues.

Humidity

In São Caetano de Odivelas, the average relative humidity in September is 78%.

Rainfall

In September, the rain falls for 20.4 days. Throughout September, 51mm (2.01") of precipitation is accumulated. In São Caetano de Odivelas, Brazil, during the entire year, the rain falls for 315.6 days and collects up to 2313mm (91.06") of precipitation.

Sea temperature

In São Caetano de Odivelas, Brazil, the average seawater temperature in September is 28.6°C (83.5°F).
Note: Water activities including swimming and diving are pleasurable in temperatures between 25°C (77°F) and 29°C (84.2°F), ensuring comfort and enjoyment for extended time frames.

Daylight

In September, the average length of the day in São Caetano de Odivelas is 12h and 7min.
On the first day of September in São Caetano de Odivelas, Brazil, sunrise is at 06:08 and sunset at 18:14. On the last day of the month, sunrise is at 05:58 and sunset at 18:05 -03.

Sunshine

The average sunshine in September in São Caetano de Odivelas is 9.1h.

UV index

January, June through December, with an average maximum UV index of 7, are months with the highest UV index in São Caetano de Odivelas. A UV Index estimate of 6 to 7 represents a high threat to health from unprotected exposure to Sun's UV rays for the average person.
Note: A maximum UV index of 7 in September translates into the following recommendations:
Steer clear of overexposure. Fair-skinned individuals can be scorched in less than 20 minutes. Try to minimize direct Sun exposure between 10 a.m. and 4 p.m., the peak period for UV radiation. Also note that objects like parasols or canopies might not provide complete sun protection. During bright days, sunglasses that offer UVA and UVB defense are recommended. Be cautious! Sand and water surfaces make the Sun's UV rays more potent.