Indian Summer

秋から冬になるときに一旦寒くなって、また暖かい陽気が一時的に戻ったときの天気を、Indian Summerというらしい。日本だったら小春日和でしょうか。そして、多分今がそのIndian Summerです。

from Wikipedia
An Indian summer is a meteorological phenomenon that occurs in the autumn. It refers to a period of considerably above normal temperatures, accompanied by dry and hazy conditions, usually after there has been a killing frost. Depending on latitude and elevation, the phenomenon can occur in the Northern Hemisphere between late September and mid November.