Weather in Shanghai in May

A good month. May works. It is not the peak, but nothing about it fights you. Highs average 25.3 °C, lows 16.4 °C, and rain falls on 11 days — nothing in the month is working against you.

May ranks 3 of 12 in Shanghai. Only October scores clearly higher, and the difference is small enough to be settled by price rather than weather.

Rain on 11 days, 4 of them heavy. Enough to need a plan B, not enough to need a plan around it. Nothing specialised needed — this is the month you pack for the trip rather than for the weather.

What the averages hide

The averages here are honest — no hidden extremes worth planning around. Across the twenty years measured, the hottest May day reached 34.7 °C and the coldest night fell to 9.3 °C, and the wettest single day dropped 78 mm — roughly 74% of the month's rain in one day.

May is moderately variable: 29 mm in the driest year against 214 mm in the wettest, around an average of 105 mm. Roughly two Mays in three land near that average, and the third does something else entirely.

Wind is light at 14.2 km/h, so the temperature on the page is close to the temperature on your skin, and humidity runs at 77%, high enough to notice on the warm days without dominating them.

How May sits in the year

The month is on the way up: 5 °C warmer than April, and June adds another 3 °C. Late in the month feels noticeably different from the start of it, which is worth knowing if the trip is short. Rain is the thing that moves: June brings 5 days more of it, so the earlier half of a flexible trip is the safer half.

Daylight in May

May is at or near the longest days of Shanghai's year: 13.7 hours of daylight, gaining 0.7 hours across the month. Evenings are the real gain — dinner outdoors still happens in full light.

Sea temperature

The sea sits at about 18.3 °C in May — swimmable, but it takes a moment to commit. 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

Busy. Popular without being frantic; book the things you care about, improvise the rest.

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

May 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 — 2.1 °C warmer, 2 days more rain. Nanjing is close enough to be a coin toss — 2.2 °C warmer, 2 days less rain.

So: May works, with October the better month by 9 points if the dates can move. If they cannot, nothing here should stop you booking.

Every month in Shanghai

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