U.S. energy demand for cooling broke an August record as air conditioning use remained elevated. Matt Rogers at Commodity Weather Group reported August reached 376 population-weighted cooling degree days (CDD), the highest in 76 years of records.
Cooling degree days measure the energy required to maintain indoor temperatures at 65 degrees Fahrenheit. The population-weighted metric prioritizes demand in densely inhabited areas, making it a critical gauge for energy markets and power grid operators.
September is tracking to become the hottest on record, surpassing 2019, according to Rogers, with expectations for a "very warm to record warm autumn." Judah Cohen, director of seasonal forecast at Atmospheric and Environmental Research JANUS Research Group, said September should be treated as a summer month given the strong warming trends, and that warm temperatures will persist for the foreseeable future.
Sustained heat across the central U.S. is keeping cooling demand and gas-fired generation elevated, according to Ryan Ward, an analyst at BloombergNEF. The pressure directly strains major grid operators including the Electric Reliability Council of Texas, the Midcontinent Independent System Operator, and the Southwest Power Pool. PJM, which manages the largest U.S. grid, extended a hot weather alert through Sept. 4.
Record-breaking August heat has coincided with higher U.S. natural gas prices due to increased demand for power-plant fuel. Population-weighted cooling degree days serve as a key metric for energy traders and power markets, quantifying cooling demand precisely where energy is consumed and influencing how the energy system prices risk for the coming months.
