What does "light summer heat" mean?

The summer heat is the first 1 1 solar term among the 24 solar terms of the lunar calendar, and it is also the fifth solar term in summer, which marks the official start of the last month of summer. Summer is the last solar term in summer, which is between July 22nd and 23rd in Gregorian calendar every year.

On July 7th or 8th every year, when the sun reaches longitude 15, it is considered as a slight summer heat.

The summer heat is also a season that reflects the degree of summer heat, which means the weather is very hot.