What a week of 105-degree days does to a Texas electric bill

On August 19, 2026, ERCOT issued an Operating Condition Notice for an extreme hot weather event, covering August 20 through August 25 in its North Central and South Central regions. Through August 24 it made no request to conserve electricity, declared no grid emergency and issued no Weather Watch. Its records page lists a weekend peak demand of 89,891 megawatts on Saturday, August 22, above the 88,018 megawatts of August 16. Like every recent figure on that page, that peak is marked unofficial until settlement.

At Dallas–Fort Worth International Airport the National Weather Service recorded highs of 105°F on August 20, 99°F on August 21, 105°F on August 22, and 109°F on both August 23 and August 24. August 22, 23 and 24 each set or tied the record for the date, and the 109°F on August 24 broke a record of 107°F that had stood since 2023. Overnight lows across those five days were between 80°F and 86°F, five to eleven degrees above normal for the dates.

The heat index and the air temperature are different measurements, and on August 25 both were 109 in separate parts of Texas. The National Weather Service defines the heat index as "a measure of how hot it really feels when relative humidity is factored in with the actual air temperature". Its Fort Worth office had an Extreme Heat Warning in effect for portions of North and Central Texas, for "high temperatures up to 109". The same day, its Houston office had a Heat Advisory in effect for southeast Texas, for "heat index values up to 109".

Measured across the whole day rather than at its peak, August 24 was the hottest of the five days. Dallas–Fort Worth averaged 98°F, which the National Weather Service calculates as the midpoint of the day's high and low. The normal for that date is 85°F. The Weather Service records August 24 as thirteen degrees above it.

Air-conditioner ratings are measured with 95°F air entering the outdoor unit. Carrier's published performance table for one of its models shows that machine producing less cooling from more electricity when the air is hotter than that: at 95°F it delivers 18,000 Btu of cooling an hour and draws 1.50 kilowatts, and at 105°F it delivers 16,920 Btu an hour and draws 1.67 kilowatts. With overnight lows above 80°F, there was no cool part of the day.

A bill that arrives during a heat wave may not cover the heat wave. Texas rules require a residential bill in the competitive market to state the service period it covers, and meter reading dates differ from one address to the next. The days that felt expensive can belong to the next billing cycle rather than this one.