Since the "plum blossoms" began on July 4, Shanghai has experienced high temperatures of nearly 40°C for several days. Orange warnings for high temperatures have been issued for six consecutive days. During this period, Xujiahui Weather Station once topped the list of high temper

Since the "plum blossom season" on July 4,

the high temperature in Shanghai has been nearly 40℃ for several days.

So far, has issued high temperature orange warnings for six consecutive days.

During this period, Xujiahui Weather Station

once topped the list of high temperatures in the country.

It’s not just Shanghai. With the significant strengthening of the subtropical high pressure, various places in the Yangtze River Delta have entered the typical midsummer season.

The high-temperature "baking" that seamlessly connects with the rainy season "hits" the free shipping area by surprise.

Zhejiang reaches the top of the list of "hottest in the country"

The high temperature after the rainy season is the most obvious in Shanghai and Zhejiang.

Judging from the data of the past 30 years, this year was the hottest month in early July in Shanghai.

From July 1 to 8 this year, Shanghai had seven high-temperature days, the highest in the past 30 years, with the average maximum temperature being 36.38°C.

In addition, this year Shanghai also has the longest "high temperature and heat wave". "High-temperature heat wave" refers to a high-temperature weather process that occurs for more than three consecutive days. The previous maximum was 4 consecutive days in 2022, but this year it is 7 days.

Judging from the whole month of July, the high temperature in Shanghai will continue. It is expected that there will be a total of 13 high temperature days in July, ranking second only to the 19 days in 2022 in the past 30 years.

Similar to Shanghai, high temperatures occur frequently in most areas of Zhejiang, with the highest temperatures exceeding 35°C in recent days, and it has repeatedly occupied several places in the top ten high temperature lists in the country.. According to data from the China Meteorological Administration, Zhejiang accounted for 8 of the top ten high temperatures from 0:00 to 18:00 on July 8, with the highest temperatures in Nanxun, Yuhang, and Jiangbei all exceeding 40°C.

For example, in Yuhang, as of July 8, the highest temperature has exceeded 35°C for seven consecutive days, and the highest temperature has exceeded 40°C for three consecutive days, setting a record for the same period in the past ten years.

Judging from the temperature in the past ten years, although there are high temperature days in Yuhang in July, they rarely exceed 40℃. Only 7 days occurred in 2017, and they were all at the end of July.

Although Jiangsu and Anhui have not entered the top ten high temperature lists in the country, they have issued yellow high temperature warnings for several consecutive days, especially in southern Jiangsu such as Wuxi, Suzhou, Changzhou, and southern Anhui such as Xuancheng, Huangshan, and Tongling.

Precipitation is higher than the average in previous years

In fact, since the beginning of May this year, precipitation in three provinces and one city has also been higher than the average in previous years.

Among them, Anhui Province has the most precipitation. According to data from the China Weather Network, as of July 3, the cumulative precipitation in Anhui Province reached 315.29 mm, which is 2.02 times the average for the same period in previous years. The precipitation in Jiangsu, Shanghai, and Zhejiang is also about 1.5 times the average in previous years.

The top six cities in terms of precipitation during this rainy season are all in Anhui Province. Mount Huangshan has the most rainfall, with a cumulative precipitation of 993.6 mm.

It can be said that since the beginning of the plum season this year, the precipitation in the Yangtze River Delta has ranked first in the same period in history. Anhui's precipitation ranked fourth during the same period in history, Zhejiang ranked fifth during the same period in history, and Shanghai and Jiangsu both ranked sixth during the same period in history.

The same is true from the hydrological station.

According to incomplete statistics, as of July 5, during this rainy season, a total of 46 hydrological stations on the Yangtze River system in Anhui Province have exceeded the warning line, with an average of more than 1.17 meters. Among them, the Xinqiao Gate Station in Ma'anshan City has the most exceeded warning water levels, with the peak reaching 11.54 meters during the flood season, exceeding the warning water level by 2.04 meters.

Multiple factors lead to extreme weather

High temperature and rainy weather are the characteristics of the Yangtze River Delta region during this season. This is due to the influence of periodic atmospheric circulation: the southwest monsoon brings sufficient water vapor and thermal conditions, resulting in stable rain belts in the south and heavy rainfall.

After the plum blossoms appear, the Yangtze River Delta is controlled by the subtropical high pressure, and downdrafts prevail. Low-level water vapor is difficult to form clouds and cause rain. More solar radiation reaches the ground, causing the ground and near-surface atmosphere to gain more heat. The temperature rises, and continuous dryness occurs. , hot weather with little rain.

However, global warming causes high-temperature weather to become more frequent. At the same time, the higher the atmospheric temperature, the more moisture it contains, increasing the frequency and intensity of heavy rainfall events. For every 1°C global warming, daily extreme precipitation Events are expected to intensify by about 7%.

In addition, global warming will also affect atmospheric circulation patterns, exacerbating the instability of the climate system, leading to an increased probability of heat waves or heavy rainfall in some areas.

According to the "China Climate Change Blue Book (2024)", the number of warm day days in China increases by an average of 6.7 days every 10 years, and the cumulative number of rainstorm days nationwide increases by 4.1% every 10 years. Under the background of global warming, extreme weather events in my country will show an increasing trend in the future.

Finally, El Niño "contributes" to extreme weather.

The El Niño event that began in May last year will warm the surface water in the eastern Pacific and increase the global average temperature. At the same time, the lagging influence of El Niño also makes the Yangtze River Basin and Jiangnan areas more prone to floods.

According to the forecast of the meteorological department, the temperature will drop slightly from the 10th to the 11th as the subtropical high weakens. However, it is expected that the temperature in southern Jiangsu, southern Anhui, Shanghai, and Zhejiang this summer will be higher than in previous years.