Dressing index is more or less appropriate.

Somatosensory temperature 15℃, dressing index 5. Grade 5 is a transitional season clothing for spring and autumn, which is suitable for jackets, vests, trousers, jackets, suits, thin sweaters and other spring and autumn clothing. Old and infirm: coat or windbreaker plus sweater. From single clothes, coats, windbreakers to sweaters, the clothing thickness is 4-15 mm.

Grade 5: windbreaker, overcoat, overcoat, sweater, wool suit, suit, winter clothes.

The climate in spring and autumn is changeable, so it is suggested to choose clothes for going out according to the suitable temperature. Extended data

"26-degree dressing rule" means that every material of clothes has its corresponding cold-resistant temperature. For example, thick down jacket is equivalent to 9℃, thin down jacket is equivalent to 6℃, slightly thick cotton-padded jacket is 5℃, thick sweater with cotton vest is 4℃, fleece sweater with thin coat is 3℃, thick cotton-padded jacket is 2℃, thin cotton-padded jacket 1℃ and so on.

"Law" points out that since the most comfortable temperature of human body is 26℃, the most suitable way to dress is that the clothing temperature and weather temperature add up to 26℃. Therefore, if the outdoor temperature is 13℃, you should wear thick sweaters and thick down jackets (13+4+9=26) to make yourself most comfortable.

As for the source of this statement, it is said that the "rules" first came from a female doctor in a city hospital of traditional Chinese medicine. The doctor observed her daughter's dress at different temperatures and came up with this rule after three months.

However, due to the differences in physique, health status and environment, how much clothes to wear varies from person to person and from environment to environment, and it is impossible to quantify according to the formula. The principle of dressing in autumn and winter is to keep warm and comfortable, and the increase or decrease should also follow the natural perception of your body.

References:

China Top Ten Brand Network-Temperature and Dress