Expanding over an area of 9.5 million sq km,China's climate and weather conditions vary to a great extent. From the tropical and subtropical climate in southeastern coastal China, to the subarctic climate in the north, it knows more biodiversity as well as a greater range of weather conditions than most countries. When it comes to the range of weather conditions, China is similar to the U.S. in many ways. The climate in China, however, tends to be more extreme, and the differences between the regions are greater. One notable influence is the summer monsoon - a wind that causes great rainfall during the summer (mostly dominant in the Indian ocean.) The Asian monsoon, a cold, dry wind, has a major influence on China's climate, blowing from central Siberia, and bringing dry and cold weather conditions to the north and the central China north of the Yangtze river. During the summer, warm winds blow from the Pacific ocean, and typhoons cause heavy rains in the coastal area from July to November. The South, Southwest and Central China have a mild, subtropical climate, with summer temperatures at the ideal 26 °C (79 °F) and an average winter temperature of 4°C (39°F). The most southern areas have tropical climates, with an average summer temperature of 28°C (82,4°F) , and a January temperature of 17°C (63°F). Rainfall is abundant in southern China during the summer months; estimated at 990 mm annually.

On high altitudes, the air is fresh and clean, and the climate very cold

In the North, summers are warm with mild showers, and winters very cold and dry. Rainfall is less than 760 mm annually, and varies greatly from one season to another. The climate of the Northeast is even colder than that of North China, with temperatures of -20°C (4°F) in January, and less precipitation (mainly during summer, from 510 to 760 mm annually). An arctic or near arctic climate is only to be found in the Tibetan Plateau, an elevated area with little rainfall (less than 100 mm annually) and temperatures from 15°C (59°F) in July to -2°C (28.4°F) in January. Northwest China and the Mongolian Steppe are characterized by dessert and steppe climates, where temperatures in January average below -10°C (50°F) and over 20°C (68°F) in July.Because of long periods of drought and poorly developed methods of agriculture, dust storms have become common during spring. Dust blows mostly to the southern China and Taiwan, and sometimes reaches the west coast of the United States. Control of pollution, water treatment and erosion have become major issues in China's relations with neighboring countries, who are very familiar with the country's growing environmental problems.