全美“极度注意”级别(≥32°C)以上的天数 (IMAGE) University of Southern California Caption 全美“极度注意”级别以上(≥32°C)的高温天数平均值因地区而异。高温是通过热指数(Heat Index)测量的。数据涵盖2010年至2016年的年度平均值。 Credit USC/Eunyoung Choi Usage Restrictions Use with credit License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.