根据温度标准, 分发专家宣布夏天已经开始. Delivery experts declare summer has begun based on temperature benchmarks.

运输专家表示, 夏季正式开始. Delivery experts claim the official start of summer has arrived. 根据他们所说的温度标准, 当平均气温达到一定值时就开始季节. They cite specific temperature benchmarks, suggesting the season begins when average temperatures hit a certain threshold. 这项新标准取代了传统的日历确定季节. This new standard replaces traditional calendar dates for defining the season.