Weather in Hiroshima in August

Shoulder season. August sits in between. You will get good days and you will lose some. The heat itself is manageable at 31.8 °C, but 83% humidity is what you will actually feel.

August ranks 8 of 12 in Hiroshima: past the worst of the year but short of October, which is the month to book if the dates are open.

Rain on 11 days, 4 of them heavy. Enough to need a plan B, not enough to need a plan around it. Natural fibres and a second shirt for the day. At 83% nothing dries, including you.

What the averages hide

Averages flatten a month, and this one hides a few things: 25 days top 30 °C, making the heat continuous rather than occasional. Across the twenty years measured, the hottest August day reached 37 °C and the coldest night fell to 16.5 °C, and the wettest single day dropped 71 mm — roughly 58% of the month's rain in one day.

August is moderately variable: 13 mm in the driest year against 302 mm in the wettest, around an average of 122 mm. Roughly two Augusts in three land near that average, and the third does something else entirely.

Wind is light at 6.1 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 83%, high enough to notice on the warm days without dominating them.

How August sits in the year

This is a turning point in the year — July and September sit on opposite sides of it, so the month contains the change rather than following it.

Daylight in August

13.5 hours of daylight, losing 0.9 hours across the month. That is between Hiroshima's extremes of 14.4 and 9.9 hours, so days are long enough not to constrain the plan.

Sea temperature

The sea sits at about 26.9 °C in August — warm enough to stay in as long as you like. This is the warmest the water gets all year.

How busy it gets

Shoulder. The value months — prices ease off and you get the place closer to itself.

Crowd levels are estimated from climate desirability and school-holiday calendars, not from visitor numbers.

August in Hiroshima versus nearby

If Hiroshima is one option among several, the nearby comparison is worth making. Kitakyushu is close enough to be a coin toss — 2.3 °C cooler, 5 days more rain. Fukuoka is the weaker option in August — within a degree on temperature, 5 days more rain.

So: August is a compromise. October is 27 points better and is what Hiroshima is actually like at its best — worth moving the trip for if that is possible, and worth adjusting expectations for if it is not.

Every month in Hiroshima

See all twelve months in Hiroshima, or where else to go in August.