Shanghai Enters the Hottest 40 Days of the Year

Credit: Imaginechina

Caption: Pedestrians carry umbrellas for shade as temperatures hit 40 degrees Celsius in Shanghai during the start of the "Dog Days" of summer.

Shanghai has now entered the hottest period of the year, referred to in traditional Chinese culture as futian 伏天. This year's stretch will last 40 days, 10 more than last year.

Today's weather

Expect sun and clouds through Thursday, with a chance of afternoon or evening showers. Morning lows will range from 28 to 31 degrees Celsius. Afternoon highs could reach 39 to 40 degrees.

Winds will blow gently from the south to southwest, a bit stronger near the river and coast. Humidity will swing widely, from 45 percent to 85 percent.

Try to stay indoors during the hottest hours. If you head out, carry an umbrella that works for both sun and rain.

What comes next

Thursday and Friday will stay hot, with highs of around 36 to 37 degrees and more scattered thunderstorms.

Rain moves in on Saturday, and the high should drop to around 34 degrees. But nights will stay warm, with lows still near 28 to 29 degrees, so the heat won't fully let up.

Credit: Imaginechina

Caption: Shanghai issued an orange heat alert as scorching temperatures baked the Bund and its few visitors.

Why this year's futian is so long

Futian is China's version of the dog days of summer. It comes from an old calendar system that counts days in 60-day cycles.

The period starts on the third geng day after the summer solstice and runs in three stages: the first, middle and final fu.

The middle stage can last 10 or 20 days, depending on the calendar that year. That's why futian sometimes runs 30 days and other times 40.

A tradition over 2,000 years old

The custom dates back more than 2,000 years, to a hot summer during the Warring States Period (475-221 BC). By the Han Dynasty (202 BC-220 AD), futian had become part of the official calendar, with customs for staying indoors during the hottest hours.

Food traditions live on today. Many families eat dumplings, noodles, or mutton during futian, following an old idea of fighting heat with heat. In Shanghai's Fengxian District, mutton from Zhuanghang Town has marked the season for more than 600 years, and the suburban district still holds an annual mutton festival.

Traditional Chinese medicine also views the period as a good time for prevention. Clinics across China offer sanfu jiu, a moxibustion treatment applied during the hottest days. The idea is to build up the body's resistance before winter arrives.

Staying safe in the heat

Doctors recommend older residents skip outdoor activity during peak sun hours and drink plenty of water. Moderate exercise, like swimming or tai chi, is still fine, as long as it's not during the hottest part of the day.