September weather forecast
Oranjestad, Aruba

September, the first month of the autumn in Oranjestad, is still a hot month, with an average temperature ranging between max 32.7°C (90.9°F) and min 26.9°C (80.4°F).
An excellent water temperature of 29.1°C (84.4°F) and only 3.9 rainfall days, with 46mm (1.81") of accumulated rainfall, makes September a prime for swimming and other water activities.

Temperature

September is the warmest month in Oranjestad, with an average high-temperature of 32.7°C (90.9°F) and an average low-temperature of 26.9°C (80.4°F).

Heat index

The average heat index in September is computed to be a life-threatening hot 45°C (113°F). Beware: Heat cramps and heat exhaustion are very likely. Heatstroke is imminent with prolonged activity.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature', 'apparent temperature', 'feels like', or 'real feel', is an index that combines air temperature and relative humidity to determine the human-perceived temperature equivalent. This effect is subjective, depending on the activity and individual's heat perception influenced by various reasons (pregnancy, clothing, metabolic differences). 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.
To prevent overheating and help regulate its internal temperature, the human body sweat and rely on the evaporation to cool down. A higher relative humidity affects normal body cooling by reducing the evaporation rate, subsequently lowering the rate at which the body cools and increasing the perception of heat. If the body can not disperse the excessive heat and body temperature reaches conditions of hyperthermia, above 37.5°C (99.5°F) to 38.3°C (100.9°F), thermal conditions are potentially life-threatening.

Humidity

The average relative humidity in September in Oranjestad, Aruba, is 76.8%.

Rainfall

In Oranjestad, during 3.9 rainfall days, 46mm (1.81") of precipitation is typically accumulated. Throughout the year, there are 64.6 rainfall days, and 472mm (18.58") of precipitation is accumulated.

Sea temperature

In Oranjestad, the average water temperature is 29.1°C (84.4°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

The average length of the day in September is 12h and 11min.
On the first day of September, sunrise is at 06:29 and sunset at 18:50. On the last day of the month, sunrise is at 06:29 and sunset at 18:30 AST.

Sunshine

In September, the average sunshine in Oranjestad is 6h.

UV index

The months with the highest UV index in Oranjestad are February through September, with an average maximum UV index of 12. A UV Index estimate of 11, and higher, represents an extreme threat to health from unprotected exposure to Sun's UV rays for the average person.
Note: The average daily UV index of 12 in September transform into the following instructions:
Practice all-important precautions. Light skin people may get burned in less than 5 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. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects. 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 reflection of water and sand dramatically increases exposure to the UV rays.