Parts of the nation weren't imagining it was a hot summer. It was blistering, and that sent July's electricity demand soaring, taking prices with it.

In Texas, ERCOT set a daily peak demand record July 18—which it promptly broke the very next day when demand hit 73.3 gigawatts on July 19, the Energy Information Administration said in its Electricity Monthly Update, issued Sept. 25.

"This is an astounding 2.2 GW above the earlier record of 71.1 GW set on August 11, 2016. Peak demand records are typically just above previous peaks, not a 2.2 GW leap as recorded in ERCOT," the report said. "This record was shattered due to very high temperatures, with hundreds of high temperature records broken in July across the state, and high population growth that has continued for many years."

EIA also said both ISO New England and New York ISO saw 12-month high demand levels during July, though the report noted that "both of these demand levels fell far short of all-time records on both systems."

Along with temperature and demand, prices also soared.

"Wholesale electricity prices set record highs at many locations in the West as an intense heat wave covered much of the region. Demand on both the electricity and natural gas transmission systems was high enough for many utilities to issue curtailment warnings and pleas to the public to reduce energy consumption," EIA said.

"Wholesale electricity prices reached $377/MWh in Southern California (CAISO), $351/MWh in Texas (ERCOT), $291/MWh in the Southwest (Palo Verde), $266/MWh in Northern California (CAISO), and $230/MWh in the Northwest (Mid-C). These extremely high power prices were recorded on July 18 in Texas (ERCOT), July 24 in California (CAISO) and the Northwest (Mid-C), and on July 25 in the Southwest (Palo Verde)," the report said.