Extreme Heat No Longer Confined to Summer, Study Finds

A recent study of four-plus decades of global weather records found that seasonal norms have been replaced by an expanded summertime with a surge in extreme heat days, extending into spring and fall. According to lead author Casey Ivanovich, extreme heat extremes are becoming more frequent, intense, and lasting longer. The study isolated the hottest 5% of days occurring around the globe using data from NASA and the European Centre for Medium-Range Weather forecasts. Researchers found that extreme heat days are increasing in both spring and fall globally, but these shifts vary across regions. For example, Phoenix, Arizona, is experiencing an earlier wet heat season and a later dry heat season, which cannot be explained by the current research.