Weather in Osaka in December

Shoulder season. December sits in between. You will get good days and you will lose some. Highs sit at 11.1 °C and the day is short; this is an indoors-with-excursions month, not an outdoors-all-day one.

December ranks 8 of 12 in Osaka: past the worst of the year but short of May, which is the month to book if the dates are open.

Rain on 9 days, 2 of them heavy. Enough to need a plan B, not enough to need a plan around it. Layers, and a genuinely waterproof outer — at 11.1 °C the difference between a good day and a miserable one is entirely down to what you are wearing.

What the averages hide

Averages flatten a month, and this one hides a few things: 3 nights fall below freezing. Across the twenty years measured, the hottest December day reached 24 °C and the coldest night fell to -2 °C, and the wettest single day dropped 72 mm — roughly 95% of the month's rain in one day.

December is statistically steady but not small: the year-to-year variation is modest in relative terms, yet the wettest December on record still delivered 141 mm against 29 mm in the driest. In a month this wet, even a tame spread is a lot of rain in absolute terms — the 76 mm average is a reasonable planning figure, not a promise.

Wind is light at 7.1 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 84%, which at 11.1 °C means damp rather than muggy — the kind of cold that gets into a coat and stays there.

How December sits in the year

The month is on the way down: 5.9 °C cooler than November, with January dropping another 2.6 °C. The first week and the last are not the same trip.

Daylight in December

December sits at the dark end of Osaka's year — 9.8 hours of daylight against 14.5 at midsummer, holding steady all month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

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

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.

December in Osaka versus nearby

If Osaka is one option among several, the nearby comparison is worth making. Kyoto is the weaker option in December — within a degree on temperature, 9 days more rain. Hamamatsu is a better bet in December — 2.1 °C warmer, 2 days less rain.

So: December is a compromise. May is 21 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 December.