You don't need to wear long pants from 10 to 15℃. But it is still related to personal cold tolerance and whether the weather is windy or not. Older people can't stand the cold and wear it at 20 degrees. From the temperature point of view, 10 degree is the limit. If the lowest temperature is below 10 degrees, they should wear long pants, and with the decrease of temperature, the long pants should be properly thickened. In addition, if you feel cold in your legs and can't return to normal body temperature after coming back from the outdoors, you should wear long pants.

Dressings at different temperatures:

First class, heat, temperature >; 28 degrees Celsius, summer clothes: short clothes, short skirts, thin skirts and shorts are made of light cotton fabrics.

Grade II, thermal comfort, temperature between 24.0~27.9 degrees Celsius, summer dress: cotton and linen shirts, thin long skirts, thin T-shirts.

Grade III, comfortable, the temperature is between 2 1.0~23.9 degrees Celsius, and the transitional clothes in the spring and autumn period include shorts made of single-layer cotton and linen fabrics, T-shirts, thin jeans, casual clothes and professional clothes.

Grade 4, cool and comfortable, the temperature is between 18.0~20.9 degrees Celsius. Spring and autumn transitional clothes: suits, jackets, windbreakers, casual clothes, jackets, suits, thin sweaters.