Weather in Osaka in August

A hard month. August is a hard month in Osaka, and worth planning around. The heat itself is manageable at 31.8 °C, but 84% humidity is what you will actually feel.

August ranks 12 of 12 — near the bottom of Osaka's year. May is the month that works, and the swing between the two is 33 points, which is a different holiday rather than a slightly better one.

Rain on 16 days, 5 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 84% nothing dries, including you.

What the averages hide

Averages flatten a month, and this one hides a few things: 26 days top 30 °C, making the heat continuous rather than occasional. Across the twenty years measured, the hottest August day reached 35.7 °C and the coldest night fell to 16.6 °C, and the wettest single day dropped 145 mm — roughly 81% of the month's rain in one day.

August is moderately variable: 51 mm in the driest year against 481 mm in the wettest, around an average of 178 mm. Roughly two Augusts in three land near that average, and the third does something else entirely.

Wind is light at 5.3 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 84%, 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 Osaka's extremes of 14.5 and 9.8 hours, so days are long enough not to constrain the plan.

An inland climate

With no coast nearby, the year swings a fair way — 30.8 °C between the warmest afternoons and the coldest nights, wider than any coastal city at this latitude would manage.

How busy it gets

Off season. The genuine off season: cheapest by a distance, with the caveat that some tours and restaurants close entirely.

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

August in Osaka versus nearby

If Osaka is one option among several, the nearby comparison is worth making. Kyoto is close enough to be a coin toss — within a degree on temperature, the same number of rain days. Hamamatsu is a better bet in August — 3.6 °C cooler, the same number of rain days.

So: August is a compromise. May is 33 points better and is what Osaka 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 Osaka

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