After the summer, the average temperature was below 22 degrees for five consecutive days. Is it back to spring or autumn?

The situation you described is the staged low temperature after the summer, because the cold air going south is strong and dominant during this period, resulting in a lower temperature than the same period of the previous year. After the cold air weakens or moves out of the field, the temperature will still rise back to normal. The staged low temperature in summer has a great influence on agriculture and fisheries, but it generally has little influence on people's lives.