September weather forecast
Kumejima, Japan

September, the first month of the autumn in Kumejima, is still a tropical month, with an average temperature ranging between min 24.9°C (76.8°F) and max 30.2°C (86.4°F).

Temperature

September's weather displays an average high-temperature of a still hot 30.2°C (86.4°F), slightly varied from August's 31.5°C (88.7°F). In September, the recorded average low-temperature is a moderately hot 24.9°C (76.8°F).

Heat index

In September, the average heat index is appraised at a fiery hot 38°C (100.4°F). Ensure extra safety measures, heat exhaustion and heat cramps are likely. Continuous activity might result in heatstroke.
Metrics for the heat index primarily focus on shaded spots and light wind conditions. Exposure to the sun directly might heighten the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', is a value derived by merging air temperature with the humidity to convey how the climate feels. The individual's temperature perception can be influenced by numerous factors such as metabolic variations, physical activity, and clothing. Remember, direct sunlight exposure can heighten the heat impact and might increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for babies and toddlers. Young individuals are typically more threatened than adults due to their reduced perspiration. Also, the larger skin surface proportionate to their small bodies and the increased heat from their activities magnify their risk.
One way the human body deals with excessive warmth is by perspiring and allowing sweat to evaporate. In the presence of abundant moisture in the atmosphere, the cooling process through evaporation is hindered, causing the body to feel excessively warm. When heat uptake goes beyond the body's cooling mechanisms, there's a surge in body temperature, posing health risks.

Humidity

The average relative humidity in September in Kumejima is 78%.

Rainfall

In Kumejima, in September, 218mm (8.58") of precipitation is typically accumulated. During the entire year, Kumejima aggregates up to 2112mm (83.15") of precipitation.

Daylight

In September, the average length of the day is 12h and 19min.
On the first day of the month, sunrise is at 06:12 and sunset at 18:53. On the last day of September, in Kumejima, Japan, sunrise is at 06:25 and sunset at 18:20 JST.

Sunshine

The average sunshine in September is 6.8h.