How Much More Electricity Does Texas Need When Temperatures Rise or Fall One Degree?

Every Texas summer brings headlines about record power demand, and every winter brings worry about whether the grid will hold. Rarely does the coverage put a number on what is driving it, namely, how much more electricity the state needs for each additional degree. This analysis pairs five years of ERCOT’s hourly grid load with NOAA hourly temperature readings across all eight Texas weather zones and measures that number directly, once for heat and once for cold.

Because demand does not track temperature in a straight line, the study models the hot and cold sides separately, splitting them at the comfort point where Texans stop needing heat and start running the air conditioning. Each figure is then translated into a yardstick anyone can picture: the number of homes that much power could run.

Key Takeaways

• A heat wave running 15°F hotter than a normal summer day adds enough demand to power about 2.85 million homes.
• Every 1°F of Texas heat above 66°F adds enough electricity demand to power about 190,000 homes.
• Each degree of summer heat strains the Texas grid more than twice as much as a degree of winter cold.
• Texas winter demand per degree has jumped 15% in three years, so winter is catching up to summer.
• Dallas-Fort Worth sees the biggest demand spike per degree of heat, about 337 megawatts.

What a Hot Degree Costs the Texas Grid

The heat side of the curve is where the biggest numbers live.

Here is what each additional degree asks of the grid and what a full heat wave adds up to.

• Every figure starts from the grid’s comfort point near 66°F, the temperature where Texas demand is lowest.
• Above that point, every 1°F of heat adds enough electricity to power 190,000 homes, roughly 950 megawatts.
• A heat wave running 15°F hotter than a normal summer day rides that same per-degree slope, adding roughly 14,250 megawatts, enough for about 2.85 million homes.
• The 950-megawatt figure is a modeled estimate based on five years of hourly data, and its tight range of 929 to 971 megawatts means the true number is very likely within about 2% of that range.
• Cooling demand climbs in a nearly straight line, so the last degrees of a heat wave cost about as much as the first.
• Measured against the grid’s own size, each degree of heat moves almost 2% of the average statewide load.

Heat Costs More Than Cold, and Winter Is Catching Up

Winter answers the question the summer headlines never ask.

Here is what each degree below the comfort point costs and how it stacks up against heat.

• Demand bottoms out at that same 66°F comfort point, and every 1°F below it adds about 429 megawatts, roughly enough to power 86,000 homes.
• Each degree of summer heat strains the grid about 2.2 times as much as a degree of winter cold.
• A cold snap 15°F below normal, like a hard Texas freeze, adds roughly 6,400 megawatts, about 1.3 million homes’ worth.
• Over the full five years, the cold slope is about 429 megawatts per degree. Over just the most recent three years (2022–2024), it climbs to about 494, roughly 15% steeper, so winter may be catching up to summer.
• The cold estimate has a wider range than the heat estimate, about 388 to 470 megawatts, reflecting how few extreme-cold hours Texas records. Dropping the February 2021 winter storm week moved it only modestly.

Where One Degree Hits Texas Hardest

Statewide averages hide big regional gaps.

Each of the eight ERCOT weather zones has its own price per degree.

• Dallas-Fort Worth has the highest price per degree of any Texas grid zone, with about 337 megawatts of additional demand for each degree of heat.
• It leads because it has the most homes and businesses running air conditioning, not because it is the hottest region. West Texas and South Texas run hotter but pull less grid power per degree.
• On a 100°F afternoon, Dallas-Fort Worth alone needs roughly 11,000 extra megawatts of cooling demand above the comfort point.
• West Texas barely reacts to the thermostat, where the grid runs mostly on oil and gas.
• Houston ranks second on raw megawatts at about 272 per degree, followed by the Austin and San Antonio zone at about 164.
• By share of local load rather than raw megawatts, the ranking reshuffles, with Dallas-Fort Worth still on top at near 2% per degree, while Houston slips toward the middle.

The Bottom Line on Texas’s Grid 

One degree doesn’t sound like much until you see what it costs the grid. This kind of degree-by-degree view gives Texans a clearer way to think about their own power use, and a better sense of why the grid faces pressure on both ends of the thermometer, with winter now adding nearly as much strain as summer.

Methodology

Grid load by weather zone comes from ERCOT’s Hourly Load Data Archives (pulled August 2026) and hourly temperature from NOAA NCEI’s Integrated Surface Database (Global Hourly, accessed August 2026), one airport station per ERCOT weather zone, with Austin and San Antonio population-weighted for South Central.

A piecewise hinge regression on five years of hourly data, 2020 to 2024, splits demand at a comfort point (near 66°F) and fits one slope for heat and one for cold, controlling for hour, day, month, and year with Newey-West confidence intervals. Flagged values were dropped, and 2022 to 2024 and a Winter-Storm-Uri-excluded window were run as robustness checks. Far West heating is statistically indistinguishable from zero, since that zone runs on weather-independent oil and gas load.

Homes-powered figures are modeled equivalents, not counts of households served; each is the megawatts-per-degree slope times 200 homes per megawatt (ERCOT summer-peak convention; source to be confirmed before publication). Megawatts are rounded to whole numbers and homes to the nearest thousand. Homes are a modeled equivalent of grid demand, not counts of specific households.

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Fair Use Statement

The data, findings, and visuals contained in this study are free to share and republish for noncommercial purposes. Please provide a link back to Payless Power so readers can access the full research and methodology.