Weather in Shanghai in December

Shoulder season. December is shoulder season in Shanghai — cheaper, quieter, and a genuine gamble. Highs sit at 10.8 °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 Shanghai: past the worst of the year but short of October, which is the month to book if the dates are open.

Rain on 8 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 10.8 °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: 8 nights fall below freezing. Across the twenty years measured, the hottest December day reached 21.5 °C and the coldest night fell to -6.6 °C, and the wettest single day dropped 29 mm — roughly 55% of the month's rain in one day.

December is moderately variable: 9 mm in the driest year against 141 mm in the wettest, around an average of 53 mm. Roughly two Decembers in three land near that average, and the third does something else entirely.

Wind is light at 13.4 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 77%, which at 10.8 °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: 6.9 °C cooler than November, with January dropping another 2.5 °C. The first week and the last are not the same trip.

Daylight in December

December sits at the dark end of Shanghai's year — 10.1 hours of daylight against 14.2 at midsummer, holding steady all month. Sightseeing days are genuinely shorter, and an itinerary built for summer will not fit.

Sea temperature

The sea sits at about 13.8 °C in December — too cold to swim without a wetsuit. The sea peaks at 27.5 °C in August and bottoms out at 8.5 °C — water lags the air by a month or two, which is why the best swimming often comes after the best weather.

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 Shanghai versus nearby

If Shanghai is one option among several, the nearby comparison is worth making. Hangzhou is close enough to be a coin toss — within a degree on temperature, the same number of rain days. Nanjing is close enough to be a coin toss — within a degree on temperature, 1 day less rain.

So: December is a compromise. October is 31 points better and is what Shanghai 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 Shanghai

See all twelve months in Shanghai, or where else to go in December.