August weather forecast
Ishigaki, Japan

August carries forward the high heat from July while presenting the heaviest rainfall of the year at 217mm (8.54"). The increase in rainfall can lead to an uptick in relative humidity, which stands at 81% for this month. Despite the rain, daylight hours remain high, rounding off at an average of 13 hours. Consequently, there remains ample opportunity to explore the outdoors when the rain subsides. Visitors can still enjoy beach activities owing to the sea temperature holding steady at 29°C (84.2°F).

Temperature

The months of July and August see the peak of Ishigaki's temperatures, averaging a high of 29.3°C (84.7°F).

Heat index

For most parts of August, the heat index is appraised at a sweltering 36°C (96.8°F). Exercise extra preventive actions, heat cramps and heat exhaustion are plausible. Continuous activity could result in heatstroke.
Heat index determinations are made taking into account the shade and light air movements. The heat index could see an increase by 15 Fahrenheit (8 Celsius) degrees under direct sunshine.
Note: The heat index, also known as 'apparent temperature' or 'feels like', measures the perceived warmth when incorporating the humidity present in the air. Elements of metabolic variation, physical activity, and clothing contribute to the effect of temperature on an individual. Take note that direct exposure to the sun can increase the felt temperature, possibly adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values are extremely significant for children. Youngsters generally face more threats than adults given their lesser ability to sweat. Coupled with their larger skin surface relative to their small bodies and higher heat production due to their activities, they are more endangered.
The human body has a built-in cooling mechanism through perspiration; evaporating sweat dissipates the excess heat. An increase in relative humidity disrupts body cooling by slowing the evaporation rate, thereby reducing the rate at which the body cools and amplifying the sense of heat. As body temperatures escalate without effective heat release, one might face dehydration threats.

Humidity

In Ishigaki, the average relative humidity in August is 81%.

Rainfall

August is the month with the most rainfall. Rain falls for 22.1 days and accumulates 217mm (8.54") of precipitation.

Sea temperature

July through September, with an average sea temperature of 29°C (84.2°F), are months with the warmest seawater.
Note: With water temperature from 25°C (77°F) to 29°C (84.2°F), all water activities are comfortable and delightful, devoid of discomfort even for lengthened periods.

Daylight

In August, the average length of the day is 12h and 58min.
On the first day of August, sunrise is at 06:12 and sunset at 19:27. On the last day of the month, sunrise is at 06:24 and sunset at 19:02 JST.

Sunshine

The average sunshine in August is 8.3h.

UV index

The months with the highest UV index in Ishigaki are May through September, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for the ordinary person.
Note: An average UV index of 7 in August transforms into this advice:
Stay clear of intense sun exposure. Solar protection is of utmost significance. UV radiation from the Sun is most intense between 10 a.m. and 4 p.m. Try to avoid direct sunlight during this period. Always opt for UVA and UVB-resistant sunglasses on radiant days. Be vigilant! The Sun's UV rays get a boost from sand and water reflections.