What is the proverb about coming to Yanmen in August to see geese wearing shoes?

In August of the lunar calendar, geese begin to move south. When geese fly by, the first frost will come.

Original text:

As the saying goes, people dress casually in February and August, with less summer rain and early autumn frost. In August, the geese come to open, and the frost is under their feet.

Vernacular translation:

After beginning of autumn, the weather turned cold, so there was no need for a fan. The weather changed from cold to hot in February, from hot to cold in August, and began to change from hot to cold. Coupled with physical differences, people's clothes are naturally different. When there is little rain in summer, autumn frost comes early. In August of the lunar calendar, geese begin to move south. When geese fly by, the first frost will come.