ERCOT Reset Every 4CP-Month Demand Record in 2026
ERCOT set new demand highs in June, July, August, and September. Heat helped, but the size of the increases—especially July’s 8,170 MW jump—shows how quickly Texas’s underlying load is growing.
ERCOT entered the 2026 summer with monthly demand records of 80,826 megawatts for June, 82,964 MW for July, 85,508 MW for August, and 84,470 MW for September. By mid-September, all four marks had been exceeded. The scale matters: the new highs are not just a story about hot afternoons. They show a Texas grid carrying substantially more underlying demand before weather adds the final push.
June through September are also ERCOT’s Four Coincident Peak, or 4CP, months. Transmission charges for many large customers are influenced by their demand during the system’s highest 15-minute interval in each of those four months. A monthly hourly demand record therefore signals a high-exposure day, but it is not automatically the final settled 4CP interval. ERCOT’s settlement data determines that separately.
The four records at a glance
- June: 82,796 MW versus 80,826 MW — up 1,970 MW, or 2.4%. Final settlement value.
- July: 91,134 MW versus 82,964 MW — up 8,170 MW, or 9.8%. Preliminary.
- August: 90,817 MW versus 85,508 MW — up 5,309 MW, or 6.2%. Preliminary.
- September: 88,492 MW versus 84,470 MW — up 4,022 MW, or 4.8%. Preliminary season-to-date value; not yet posted in the September cell of ERCOT’s Demand and Energy workbook as of publication.
How much was heat, and how much was growth?
June looks mixed. National Weather Service outlooks warned that heat risk would increase during the middle and latter part of the month, and heat advisories covered parts of East Texas around the June 18 peak. But the record rose a relatively modest 2.4 percent from June 2023, consistent with ordinary summer heat acting on a larger load base.
July was also mixed, with the strongest evidence for structural growth. Extreme Heat Warnings were active on July 22, including dangerous heat-index values across North Texas and the Houston area. Yet NOAA ranked Texas’s July only the 22nd warmest in the state record. A 9.8 percent demand jump without a comparably exceptional statewide month points to new data centers, industrial facilities, commercial activity, and population-driven cooling load doing much of the work.
August had the clearest sustained-heat contribution. Around the August 24 record, NWS offices reported triple-digit highs and heat-index values near 109–111°F in parts of South and Central Texas. Deep South Texas was on track for one of its hottest Augusts on record. Even so, the 6.2 percent increase over the extreme August 2023 benchmark would have been difficult to reach without a higher structural load floor.
September was heat-assisted and growth-amplified. Through mid-month, Corpus Christi reported an average high near 99°F—more than 8°F above normal—and heat advisories warned of heat-index values around 109°F. That late-season heat raised cooling demand, while the new 88,492 MW high shows that the grid no longer needs peak-August conditions to approach 90 GW.
What the reset means
For forecasters, 2026 changes the baseline. Weather models still determine the timing and shape of the daily peak, but historical temperature-to-load relationships can understate demand when large, weather-insensitive loads are added quickly. For 4CP exposure, the practical lesson is similar: watch the hottest high-load intervals, but do not assume the day’s hourly record will become the final 4CP value.
The four-record sweep is best understood as a combined signal. Heat supplied the trigger each month; structural growth increased the amount of demand available to respond. July made that shift unmistakable, and August and September showed that it persisted through the rest of the 4CP season.
Sources and status note
Values are rounded from ERCOT’s Net System Maximum Hourly Demand series. In the 2026 Demand and Energy Report available at publication, months marked with an asterisk have completed final settlements: June is final; July and August are preliminary. September’s supplied season-to-date value remains preliminary and may change when ERCOT posts and settles the month. Monthly hourly peaks and final 15-minute 4CP intervals are different measures.
- ERCOT — 2026 Demand and Energy Report and Peak Demand Records (ercot.com).
- NOAA National Centers for Environmental Information — July 2026 National Climate Report (ncei.noaa.gov).
- National Weather Service — 2026 Texas heat advisories, climate summaries, and seasonal outlooks (weather.gov).
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