Starting August 1, households across Massachusetts will feel the impact of higher electricity prices. National Grid and Eversource are increasing supply rates as extreme heat pushes demand higher.

Western MA customers will see Eversource’s supply rate rise to 13.49 cents per kWh, while National Grid customers will move to 15.5 cents. For many homes, that means an extra $5 or more per month, with prices locked in through January.

Utilities note that Massachusetts residents use 30% more power in summer, and the spike in usage is a major driver of bill increases. Consumer advocates say now is a smart time to review energy choices or explore cost-saving alternatives.