Across 376 counties in eleven states from California to Florida, the average cost of cooling a home rose by more than $15 a year between 2018 and 2024, or $105 in total, according to Duke University's Nicholas Institute. In the hardest-hit California counties, electricity rate hikes drove 87% to 94% of the rise and hotter weather 6% to 14%.

Source: Duke University (2026-08)