Why does the diurnal temperature range decrease with increasing latitude?

The diurnal variation in solar height is small in areas with higher latitudes. The diurnal temperature range decreases with increasing latitude. This is because the change in the sun's altitude throughout the day decreases with increasing latitude. Generally, the daily temperature range in tropical areas is about 12℃; in temperate areas, the daily temperature range is 8.0~9.0℃; in the polar circle, the daily temperature range is 3.0~4.0℃.

Generally, the diurnal temperature range is greater in summer than in winter, but in mid- and high-latitude areas, the maximum diurnal temperature range of the year occurs in spring. Although the sun's altitude angle is large in summer, the sunshine hours are long, and the daytime temperature is high, due to the long days and short nights in mid- and high latitudes, the cooling time is not long, so the nighttime temperature is also high, so the diurnal temperature range in summer is not as large as in spring.

Extended information

Factors affecting the annual temperature range

(1) Latitude. The annual temperature range increases with the increase in latitude. This is because as the latitude increases, the annual variation of solar radiation energy increases (the height of the sun at noon and the length of day and night vary greatly within the year).

For example, the annual temperature range in my country’s Xisha Islands (16°50′N) is only 6°C, Shanghai (31°N) is 25°C, and Hailar (49°13′N) reaches 46°C. The annual temperature range in low latitudes is very small, while in high latitudes the annual temperature range can reach 40 to 50°C.

(2) The thermal properties of sea and land are different. For sea and land at the same latitude, the difference in heat income between winter and summer in the mainland is larger than that of the ocean. Therefore, the closer to the ocean, the greater the impact of the ocean. , the smaller the annual temperature range, the further away from the ocean, the less affected by the ocean, the greater the annual temperature range. Under normal circumstances, the annual temperature range in temperate oceans is 11°C, and the annual temperature range in continents can reach 20 to 60°C.

(3) Topography: Generally speaking, highlands are smaller than depressions and valleys. The higher the altitude, the smaller the annual range.

(4) Weather, areas with more clouds and rain are smaller than areas with less clouds and rain.

Baidu Encyclopedia-Diurnal temperature range