Dividing map of seven temperature zones

Based on the accumulated active temperature of each region, the zones are divided according to the heat indicators required for agricultural production:

1. 23°26′ N (Tropic of Cancer) to 23° 26′ S (Tropic of Capricorn) is the tropics.

2. The northern latitude (southern latitude) 23°26′ to the northern latitude (southern latitude) 66°34′ (Arctic Circle and Antarctic Circle) is the north and south temperate zones.

3. From 66°34′ north latitude (southern latitude) to 90° north latitude (southern latitude) are the north and south cold zones.

Most of China is located in the north temperate zone, and a small part is located in the tropics; it is divided into cold temperate zone (northern Heilongjiang, eastern Inner Mongolia), mid-temperate zone (Northeast, most of Inner Mongolia, northern Xinjiang), and warm temperate zone (Yellow River Most areas in the middle and lower reaches, southern Xinjiang);

Subtropical (south of the Qinling Mountains and the Huaihe River, east of the Qinghai-Tibet Plateau), tropical (southern Yunnan, Leizhou Peninsula, southern Taiwan and Hainan Province) and plateau climates.

Extended information:

Proportion of China’s temperate zone area:

Among the various temperature zones, the cold temperate zone only accounts for 1.2% of the total land area. Most of the Qinghai-Tibet Plateau has an alpine climate, accounting for 26.7% of the total land area. The remaining areas accounting for 72.1% of the total land area belong to the mid-temperate zone, warm temperate zone, subtropical zone, and tropical zone. Therefore, China mainly has a warm climate.

World climate:

1. Low-latitude climate

The climate at low latitudes is mainly controlled by equatorial air masses and tropical air masses. The main circulation systems that affect climate are the equatorial convergence zone, the Wacker circulation, trade winds, equatorial westerly winds, tropical cyclones and subtropical highs.

The radiation balance of the earth-atmosphere system is extremely high throughout the year, so the temperature is high throughout the year. The average temperature in the coldest month is above 15-18℃, and the possible evapotranspiration of water throughout the year is above 130cm. This zone can be divided into 5 climate types, of which the tropical arid and semi-arid climate types can be divided into 3 subtypes.

2. Mid-latitude climate

This is a zone where tropical air masses and polar air masses compete with each other. The main circulation systems that affect climate include polar fronts, prevailing westerly winds, extratropical cyclones and anticyclones, subtropical highs and tropical cyclones. The radiant energy balance in this zone changes greatly throughout the year, so the four seasons are distinct. The average temperature in the coldest month is below 15 to 18°C, and there are 4 to 12 months with an average temperature above 10°C.

The possible evapotranspiration throughout the year is between 130 and 52.5cm. Non-periodic changes in weather and seasonal changes in precipitation are significant. Coupled with the large continental area in the mid-latitudes of the Northern Hemisphere, the climate in this zone is even more complex due to the thermal contrast between land and sea and the towering and massive terrain. This zone is divided into 8 climate types.

3. Plateau mountain climate

As the height increases in the highlands, various climate elements also change, resulting in obvious vertical zonal characteristics of the alpine climate. In order to distinguish climates affected by altitude from those affected by factors such as latitude, and because alpine climate is limited to a local scale, highland climate is classified as a separate category and is not included in the lowland classification system.