August weather forecast
Hiroshima, Japan

Wide fluctuations in Hiroshima's weather patterns become evident in August when the rainfall significantly lowers down to 111mm (4.37") from 259mm (10.2") in July. Despite the reduction in rainfall, temperatures remain high with the warmest sea temperatures of the year crowning August as a preferred time for beachgoers. The humidity, too, stays high ensuring residents and visitors are reminded of the lingering summer heat. A significant amount of sunshine persists, acting as a reminder of the ongoing summer season. The UV Index remains high, so protective measures against the sun remain important.

Temperature

August temperatures tend to peak at an average high of 32.5°C (90.5°F) and dip to a low of 24.8°C (76.6°F).

Heat index

For August, the heat index is appraised at a scorching 42°C (107.6°F). Implement additional preventive actions, heat cramps and heat exhaustion are potential hazards. Heatstroke could follow prolonged activity.
Understand that the heat index values take into account shaded locations and mild winds. Direct sunlight exposure may result in a rise of the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'felt air temperature', shows a temperature sensation when both heat and moisture conditions are combined. The individual's impression of temperature can be affected by numerous factors such as metabolic variations, physical exertion, and attire. It is important to note that direct sunlight can intensify the weather impact, potentially raising the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially vital to children. Children frequently do not understand the need for recuperation and hydration. Thirst, being a late manifestation of dehydration, underlines the need to hydrate frequently, especially when engaging in prolonged physical exercises.
Perspiring is the body's way of cooling down, particularly by allowing sweat to evaporate and take the heat with it. Under conditions of increased relative humidity, the evaporation rate lessens, causing the body to retain more heat than under less humid conditions. Overheating dangers loom when the body's heat release mechanisms are overshadowed by excessive gain.

Humidity

In Hiroshima, Japan, the average relative humidity in August is 71%.

Rainfall

In Hiroshima, during August, the rain falls for 14 days and regularly aggregates up to 111mm (4.37") of precipitation. Throughout the year, in Hiroshima, there are 190 rainfall days, and 1538mm (60.55") of precipitation is accumulated.

Snowfall

In Hiroshima, snow does not fall in April through November.

Sea temperature

With an average sea temperature of 26.8°C (80.2°F), August is the month with the warmest seawater.
Note: Surface water temperatures ranging from 25°C (77°F) to 29°C (84.2°F) are considered superb and highly pleasant for water activities over extended periods.

Daylight

In August, the average length of the day is 13h and 25min.
On the first day of August, sunrise is at 05:21 and sunset at 19:12. On the last day of the month, sunrise is at 05:42 and sunset at 18:38 JST.

Sunshine

August has the most sunshine of the year in Hiroshima, with an average of 6.8h of sunshine.

UV index

In Hiroshima, the average daily maximum UV index in August is 10. A UV Index value of 8 to 10 symbolizes a very high health risk from unsafe exposure to UV radiation for the ordinary person.
Note: The UV index of 10 in August translates into these instructions:
Protection is paramount; otherwise, swift harm can come to the skin and eyes. Remember that the sun's UV radiation is strongest between 10 a.m. and 4 p.m. Make an effort to avoid direct sun exposure during these hours. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly. Apply and frequently reapply a broad-spectrum SPF 30+ sunscreen after every two hours, or immediately after a swim or outdoor exercise. Notice! Sand and water reflections contribute to a stronger UV exposure.