September weather forecast
Boa Vista, Brazil

Shifting into September, Boa Vista's weather pattern continues to maintain a balanced phase. With rainfall reducing significantly to 89mm (3.5"), the city welcomes more sunshine hours up to 10.2 hours per day. The predominant warmth still lingers, but cooler winds signify the onset of the dry season. The low wind speeds keep the weather calm, providing a relief from the previous humid months.

Temperature

September's average high-temperature in Boa Vista stands at a still tropical 33°C (91.4°F), showing little deviation from August's 31.5°C (88.7°F). During the nights in September, Boa Vista observes an average low-temperature of 23.1°C (73.6°F).

Heat index

September's mean heat index is appraised at a scorching 44°C (111.2°F). Careful: Heat exhaustion and heat cramps are anticipated. With ongoing exertion, heatstroke becomes a possibility.
In terms of the heat index, values are set with light wind and shade conditions in mind. With 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 'feels like' or 'felt air temperature', is an amalgamation of air temperature and humidity to express the equivalent perceived temperature. A person's impression of weather can be shaped by several aspects, among them metabolic variations, pregnancy, and levels of physical activity. Be aware that direct exposure to sunlight increases heat impact and may raise the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are extremely vital to babies and toddlers. Children frequently do not comprehend the need for rest and hydration. Thirst is an advanced stage of dehydration - staying hydrated, especially during extended physical exercises, is essential.
The natural cooling mechanism in humans involves perspiration, where the evaporation of sweat balances out excessive warmth. When air moisture content is high, the cooling process through evaporation is not as efficient, leading to an ineffective body cooling process and a feeling of overheating. As body temperatures escalate without effective heat release, one might face dehydration threats.

Humidity

In Boa Vista, the average relative humidity in September is 72%.

Rainfall

In Boa Vista, in September, it is raining for 22.5 days, with typically 89mm (3.5") of accumulated precipitation. In Boa Vista, during the entire year, the rain falls for 241.8 days and collects up to 1216mm (47.87") of precipitation.

Daylight

In September, the average length of the day in Boa Vista is 12h and 8min.
On the first day of September in Boa Vista, sunrise is at 05:57 and sunset at 18:07. On the last day of the month, sunrise is at 05:49 and sunset at 17:55 -04.

Sunshine

September has the most sunshine of the year in Boa Vista, Brazil, with an average of 10.2h of sunshine.

UV index

The months with the highest UV index in Boa Vista, Brazil, are January through May, July through December, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high health vulnerability from exposure to the Sun's UV rays for the ordinary person.
Note: The maximum daily UV index of 7 in September interprets into the following recommendations:
Shield from overexposure. Defense against sun-related harm is required. UV radiation from the Sun is most intense between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. A hat with a broad brim is indispensable, filtering out up to half of UV rays.