How long before it gets cold?

It's the Millennium (9.8-9.23), the summer heat is fading away, and the weather is getting colder, which is characterized by shorter days, longer nights and large temperature difference between day and night. At this time, you can wear short sleeves during the day and add a thin coat when you go out at night. During this period, the weather changes in a cloudy or sunny way, because the temperature has not been adjusted well, which requires a process.

September 23rd 16: 20 and 3 1 sec entered the autumnal equinox, and the temperature gradually decreased on the following15th day (usually a solar term is15th day), but it did not completely cool down. It didn't get cold until the cold dew on June 8, 10, when the average temperature dropped below 20 degrees Celsius. You should wear a coat when you go out, whether in the morning or at night.