September weather forecast
São José do Piauí, Brazil

September, the first month of the spring in São José do Piauí, is a very hot month, with temperature in the range of an average high of 35.5°C (95.9°F) and an average low of 21.8°C (71.2°F).

Temperature

The advent of September observes an average high-temperature of a sweltering 35.5°C (95.9°F), nearly identical to August's 34.1°C (93.4°F). Despite the stark contrast with daytime temperatures, São José do Piauí's September nights average at an agreeable 21.8°C (71.2°F).

Heat index

The average heat index in September is appraised at a very hot 39°C (102.2°F). More preventive actions are needed, risk of heat exhaustion and heat cramps is significant. Prolonged activity may trigger heatstroke.
Be advised, the heat index considers values for conditions in shade and with a light breeze. Exposure to the sun directly might heighten the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'real feel', is a numerical representation of warmth when taking temperature and moisture levels into account. The individual's impression of temperature can be shaped by additional aspects such as metabolic variations, physical activity, and clothing. It is noteworthy to mention that direct sunlight exposure can augment the felt temperature, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are of high significance for children. Children often overlook the necessity for resting and fluid replenishment. Thirst is a late sign of dehydration - thus, it is critical to stay hydrated, especially during extended periods of physical activities.
Perspiration, followed by sweat evaporation, is the human body's chief method to maintain a balanced temperature. Higher relative humidity impedes evaporation, thus reducing heat dispersion from the body, culminating in a sensation of overheating. Increasing body temperatures can be a precursor to dehydration if the body can't shed the extra heat.

Humidity

With an average relative humidity of 42%, September is the least humid month.

Rainfall

Months with rainfall are January through July, September through December. September is the first month it rains. Throughout September, in the average 1.5 rainfall days, it receives 2mm (0.08") of precipitation. In São José do Piauí, during the entire year, the rain falls for 152.5 days and collects up to 872mm (34.33") of precipitation.

Daylight

In São José do Piauí, the average length of the day in September is 12h and 4min.
On the first day of September, sunrise is at 05:46 and sunset at 17:45. On the last day of the month, sunrise is at 05:30 and sunset at 17:40 -03.

Sunshine

The months with the most sunshine are August and September, with an average of 9.9h of sunshine.

UV index

The months with the highest UV index in São José do Piauí are September and October, with an average maximum UV index of 8. A UV Index of 8 to 10 symbolizes a very high health risk from exposure to the Sun's UV rays for average individuals.
Note: The average daily UV index of 8 in September transforms into the following instructions:
Always stay safe. Unprotected skin and eyes can get damaged rapidly. 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. To cut down UV radiation exposure by about half, sport a wide-brim hat.