autumnal

形容词 autumnal:

1. of or characteristic of or occurring in autumn
2. characteristic of late maturity verging on decline

1. The weather in June was positively autumnal.
   那六月的天气真像秋天似的。
2. The weather in September was positively autumnal.
   九月的天气确实像秋天了。
3. I feel a little cool in the autumnal night.
   在秋天的晚上，我感到一丝凉意。