September weather forecast
Dumai, Indonesia

September, the first month of the autumn in Dumai, is still a tropical month, with an average temperature varying between 32.2°C (90°F) and 24°C (75.2°F).

Temperature

The transition into September reveals an average high-temperature of a still hot 32.2°C (90°F), mirroring a close resemblance to August. In September, Dumai reports a consistent average low-temperature of 24°C (75.2°F) during the nights.

Heat index

In September, the average heat index is appraised at a life-threatening hot 45°C (113°F). Stay vigilant: Heat cramps along with heat exhaustion are expected. Heatstroke may follow prolonged exertion.
The heat index's values are generally associated with conditions in shade and light breezes. Direct sunshine exposure could raise heat index values by as much as 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'apparent temperature', is an amalgamation of air temperature and humidity to express the equivalent perceived temperature. The perception of temperature can be subjective, varying based on activity and individual heat sensitivity, influenced by factors like wind, attire, and metabolic variations. Be mindful that being in direct sunlight might mean feeling hotter, with the heat index rising by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Youths are typically more endangered than adults since they usually sweat less. Their larger skin surface concerning their smaller bodies and higher heat production due to activity further adds to their vulnerability.
The body's natural response to excessive warmth is perspiration, as it allows for cooling through sweat evaporation. An elevated level of relative humidity hinders evaporation, leading to decreased heat elimination from the body, inducing a sensation of excess heat. When the heat gained surpasses the body's cooling capacity, temperatures rise, signaling potential health concerns.

Humidity

In Dumai, the average relative humidity in September is 79%.

Rainfall

In Dumai, in September, during 24.6 rainfall days, 82mm (3.23") of precipitation is typically accumulated. Throughout the year, there are 286.4 rainfall days, and 1200mm (47.24") of precipitation is accumulated.

Sea temperature

In September, the average sea temperature is 29.4°C (84.9°F).
Note: For swimming, diving, or other water activities, the temperature range of 25°C (77°F) to 29°C (84.2°F) is perceived as exceptionally enjoyable and comfortable even for prolonged periods.

Daylight

The average length of the day in September in Dumai is 12h and 7min.
On the first day of September in Dumai, sunrise is at 06:09 and sunset at 18:18. On the last day of the month, sunrise is at 06:01 and sunset at 18:07 WIB.

Sunshine

In September, the average sunshine is 8.5h.

UV index

The months with the highest UV index in Dumai are January through September and November, with an average maximum UV index of 7. A UV Index reading of 6 to 7 represents a high health risk from unsafe exposure to UV radiation for ordinary individuals.
Note: During September, 7 as the daily maximum UV index converts into the following advice:
Employ safeguards and advocate sun safety protocols. Shielding against skin and eye damage is crucial. It's important to stay in the shade and limit exposure to the sun from 10 a.m. to 4 p.m., when UV radiation is most intense, although remember that shade structures may not provide full sun protection. For effective sun eye protection, rely on sunglasses certified for UVA and UVB resistance. Alert! UV radiation becomes sharper due to reflections from sand and water.