Review of the Record-Breaking 2023 U.S. Heat Season

The summer of 2023 will be remembered for the exceptional persistence and intensity of heat across the southern United States. Numerous cities across the southern tier of the country observed their warmest month on record, by average temperature, in July, including Miami, Tampa, Baton Rouge, El Paso, Albuquerque, Las Vegas, and Phoenix. In fact, Phoenix broke their record for warmest month by nearly 4 degrees, a remarkable new benchmark for a monthly record, with nearly every day in July setting a high temperature of at least 110 degrees Fahrenheit. In the Gulf Coast region, anomalously warm Gulf of Mexico waters contributed to oppressive humidity through much of the summer, with numerous locations in the region registering a record number of hours of heat index readings above 110 degrees Fahrenheit. Puerto Rico also set their 2nd hottest month on record in June, and some heat index readings exceeded 120 degrees Fahrenheit on the island, per the National Weather Service (NWS) office in San Juan.

This presentation will examine the 2023 U.S. heat season through an overview of the general weather pattern and meteorology, a review of notable records and statistics, Watch and Warning practices from the NWS, how a new Key Messages graphic for heat was implemented between the Weather Prediction Center (WPC) and Climate Prediction Center (CPC), and brief look at heat elsewhere in the world in 2023. A preview of some future heat-related operating capabilities at WPC will also be provided.