Core Viewpoint - The North China rainy season has been notably prolonged this year, lasting 55 days as of August 28, compared to the average of 30 days, influenced by various climatic factors such as sea temperature anomalies and persistent high-pressure systems [1][2][5]. Group 1: Rainy Season Characteristics - The rainy season began on July 5, 13 days earlier than the average start date of July 18, marking the earliest onset since 1961 [2][5]. - Cumulative rainfall in the monitoring area has exceeded the normal seasonal value by 131% as of August 25 [2][3]. - The rainy season has been characterized by high humidity and frequent heavy rainfall events, with 29 significant precipitation events recorded since the onset of the rainy season [3][4]. Group 2: Contributing Factors - Multiple factors contribute to the extended duration of the rainy season, including anomalies in equatorial Pacific sea temperatures, a strong and northward-shifted subtropical high-pressure system, typhoon activity, and geographical features [5][6]. - The subtropical high-pressure system has been particularly strong, reaching its northernmost position since 1961, facilitating the influx of warm, moist air from the south [6][7]. - The interaction between warm, moist air and cold air from higher latitudes has led to increased precipitation in North China [6][7]. Group 3: Climate Change Implications - The record-breaking rainy season is seen as a local manifestation of global climate system changes, with increasing frequency and intensity of extreme weather events attributed to climate change [8]. - Experts suggest that the duration of the rainy season exhibits significant interdecadal variability, with a trend of increasing duration observed since 2011 [7][8]. - There is a call for enhanced disaster prevention and mitigation measures in response to extreme weather, emphasizing the need for societal engagement in climate adaptation strategies [8].

Core Insights - The North China rainy season has been notably prolonged this year, lasting 55 days as of August 28, compared to the average of 30 days, marking the earliest start since 1961 [1][2][4] - The rainy season has been characterized by increased rainfall, with cumulative precipitation exceeding the normal value by 131% as of August 25 [1][2] - Multiple factors contribute to the extended duration and intensity of the rainy season, including abnormal sea surface temperatures in the equatorial Pacific and a strong subtropical high pressure system [4][5][6] Rainfall Characteristics - There have been 29 significant rainfall events since the onset of the rainy season, with 10 classified as strong and 2 as exceptionally strong [2] - Notable rainfall amounts include over 250 mm in certain areas, with specific locations like Beijing's Miyun District recording 573.5 mm and Baoding in Hebei reaching 605.8 mm [2][5] Climate Change Implications - The record-breaking rainy season is seen as a local manifestation of global climate system changes, with increasing frequency and intensity of extreme weather events [6][7] - Experts suggest that the duration of the rainy season may continue to exhibit interdecadal variability, with a trend of increasing duration observed since 2011 [6][7]

Core Viewpoint - The North China rainy season has been notably prolonged this year, lasting 55 days as of August 28, which is significantly longer than the average duration of 30 days, influenced by various climatic factors [1][2][4]. Summary by Relevant Sections Rainy Season Characteristics - The rainy season in North China began on July 5, 13 days earlier than the average start date of July 18, marking the earliest onset since 1961 [2][5]. - As of August 25, the cumulative rainfall in the monitoring area was 131% above the normal seasonal value [2]. Rainfall Events - There have been 29 significant rainfall events since the onset of the rainy season, with 10 classified as strong and 2 as exceptionally strong [3]. - Notable rainfall amounts include over 250 mm in certain areas, with specific locations like Beijing's Miyun District recording 573.5 mm and Baoding in Hebei reaching 605.8 mm [3]. Influencing Factors - The prolonged rainy season is attributed to several factors, including abnormal sea temperatures in the equatorial Pacific, a strong and shifted subtropical high-pressure system, typhoon activity, and geographical features [5][6]. - The subtropical high-pressure system has been particularly strong and has shifted northward, facilitating the influx of warm, moist air from the south [6]. Climate Change Context - The record-breaking rainy season is seen as a local manifestation of global climate change, with increasing frequency and intensity of extreme weather events [7][8]. - Experts suggest that while the rainy season's duration has shown an increasing trend since 2011, it is too early to definitively conclude that this "warming and wetting" trend will continue [7][8].

Core Insights - The article discusses the unusually long and wet rainy season in North China, which began on July 5, 2023, 13 days earlier than the average start date of July 18, marking the earliest onset since 1961 [1][2] - The average rainfall in the North China monitoring area reached 315.5 mm, which is 131% higher than the normal value of 136.6 mm [2] - The record-breaking rainfall is attributed to multiple factors, including abnormal sea temperatures in the equatorial Pacific, a strong and shifted subtropical high-pressure system, typhoon activity, and geographical influences [3][4] Summary by Sections Rainy Season Characteristics - The rainy season in North China has lasted for 52 days as of August 25, significantly longer than the typical duration of 30 days [1] - The rainy season is characterized by increased rainfall frequency, volume, and humidity, contributing to a notably damp environment [2] Factors Contributing to Abnormal Weather - The subtropical high-pressure system has been stronger and positioned further north than usual, facilitating the transport of warm, moist air from lower latitudes to northern China [3] - Historical data indicates that the combination of typhoons and the subtropical high can lead to extreme rainfall events, as seen with Typhoon "Kanu" and Typhoon "Zhu Jie Cao" [3] Climate Change Implications - The record rainfall in North China is viewed as a local manifestation of global climate system changes, emphasizing the need for improved climate adaptation and response capabilities to address extreme weather challenges [4]