ERCOT Demand Forecast Accuracy: Error, Bias and Worst Miss, 13 October to 12 November 2026

The day-ahead demand forecast for ERCOT was off by 1.4% on average (mean absolute percentage error) over 719 hours from 13 October to 12 November 2026, and 98% of hours landed within 5% of the reading. Its bias was +0.3%: it ran close to balanced on average. The largest miss was 4,703 MW (8.9%) too high at 16 Oct 2026, 12:00 CDT (UTC-05:00). Dates and times are local (America/Chicago).

Key Facts

The day-ahead demand forecast for ERCOT was off by 1.4% on average (mean absolute percentage error) over 719 hours from 13 October to 12 November 2026, and 98% of hours landed within 5% of the reading. Its bias was +0.3%: it ran close to balanced on average. The largest miss was 4,703 MW (8.9%) too high at 16 Oct 2026, 12:00 CDT (UTC-05:00).
Across 53 US grids ranked by average error over their own latest 30 day windows, ERCOT came 1 (1 is the smallest error).
On average the forecast differed from reported demand by 732 MW, against average demand of 52,809 MW.
The forecast was above reported demand in 52% of compared hours.

Forecast Error at a Glance

719 hours from 13 October to 12 November 2026

Average error1.4%

Bias+0.3%

Hours within 5%98%

Worst miss4,703 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (+129 MW per hour on average): the forecast ran close to balanced on average. The worst miss was 4,703 MW (8.9%) too high at 16 Oct 2026, 12:00 CDT (UTC-05:00): forecast 57,683 MW, reported 52,980 MW.

Source: U.S. Energy Information Administration (EIA). (US Government work, public domain) Data as of 2026-11-12. Accuracy is computed by World Power Monitor from the operator's hourly forecast and reported demand.

Forecast and Reported Demand, Last 7 Days

Local time, to 12 Nov 2026, 06:00 CST (UTC-06:00)

Hourly reported demand and the day-ahead forecast for ERCOT over the last 7 days of the window, to 12 Nov 2026, 06:00 CST (UTC-06:00). Gaps are hours with a missing, zero or implausible report.

Data to 2026-11-12

Show the data table (168 rows)

Local hour	Reported demand	Day-ahead forecast
5 Nov, 07:00	48,948 MW	48,882 MW
5 Nov, 08:00	49,868 MW	49,853 MW
5 Nov, 09:00	51,108 MW	51,043 MW
5 Nov, 10:00	52,623 MW	52,553 MW
5 Nov, 11:00	54,074 MW	53,723 MW
5 Nov, 12:00	55,805 MW	55,377 MW
5 Nov, 13:00	57,613 MW	57,056 MW
5 Nov, 14:00	59,105 MW	58,563 MW
5 Nov, 15:00	60,407 MW	59,387 MW
5 Nov, 16:00	60,746 MW	59,140 MW
5 Nov, 17:00	59,954 MW	58,493 MW
5 Nov, 18:00	59,381 MW	58,001 MW
5 Nov, 19:00	57,887 MW	56,684 MW
5 Nov, 20:00	56,377 MW	55,205 MW
5 Nov, 21:00	54,539 MW	53,628 MW
5 Nov, 22:00	52,334 MW	51,145 MW
5 Nov, 23:00	49,669 MW	48,810 MW
6 Nov, 00:00	47,683 MW	47,292 MW
6 Nov, 01:00	46,082 MW	45,586 MW
6 Nov, 02:00	45,053 MW	44,473 MW
6 Nov, 03:00	44,516 MW	44,050 MW
6 Nov, 04:00	44,843 MW	44,467 MW
6 Nov, 05:00	46,108 MW	46,348 MW
6 Nov, 06:00	48,454 MW	49,016 MW
6 Nov, 07:00	49,553 MW	50,266 MW
6 Nov, 08:00	50,641 MW	51,603 MW
6 Nov, 09:00	51,637 MW	52,917 MW
6 Nov, 10:00	52,616 MW	53,848 MW
6 Nov, 11:00	53,639 MW	54,406 MW
6 Nov, 12:00	54,596 MW	55,053 MW
6 Nov, 13:00	55,899 MW	55,961 MW
6 Nov, 14:00	56,914 MW	56,673 MW
6 Nov, 15:00	57,133 MW	56,942 MW
6 Nov, 16:00	56,505 MW	56,706 MW
6 Nov, 17:00	55,860 MW	55,983 MW
6 Nov, 18:00	55,444 MW	55,909 MW
6 Nov, 19:00	54,208 MW	54,875 MW
6 Nov, 20:00	53,078 MW	53,871 MW
6 Nov, 21:00	52,033 MW	52,519 MW
6 Nov, 22:00	50,193 MW	50,636 MW
6 Nov, 23:00	48,412 MW	48,764 MW
7 Nov, 00:00	46,501 MW	46,424 MW
7 Nov, 01:00	45,102 MW	45,183 MW
7 Nov, 02:00	44,227 MW	44,112 MW
7 Nov, 03:00	43,942 MW	43,744 MW
7 Nov, 04:00	43,687 MW	43,525 MW
7 Nov, 05:00	44,335 MW	43,900 MW
7 Nov, 06:00	45,085 MW	45,161 MW
7 Nov, 07:00	45,949 MW	46,329 MW
7 Nov, 08:00	47,787 MW	47,700 MW
7 Nov, 09:00	49,193 MW	49,202 MW
7 Nov, 10:00	50,018 MW	50,217 MW
7 Nov, 11:00	50,991 MW	51,228 MW
7 Nov, 12:00	51,916 MW	51,871 MW
7 Nov, 13:00	52,663 MW	52,285 MW
7 Nov, 14:00	53,080 MW	52,564 MW
7 Nov, 15:00	53,257 MW	52,583 MW
7 Nov, 16:00	53,017 MW	52,220 MW
7 Nov, 17:00	53,452 MW	52,635 MW
7 Nov, 18:00	53,525 MW	53,051 MW
7 Nov, 19:00	52,708 MW	52,335 MW
7 Nov, 20:00	51,948 MW	51,595 MW
7 Nov, 21:00	50,972 MW	50,644 MW
7 Nov, 22:00	49,508 MW	49,131 MW
7 Nov, 23:00	48,021 MW	47,388 MW
8 Nov, 00:00	46,634 MW	45,886 MW
8 Nov, 01:00	45,555 MW	44,706 MW
8 Nov, 02:00	44,506 MW	43,671 MW
8 Nov, 03:00	44,041 MW	43,392 MW
8 Nov, 04:00	43,882 MW	43,164 MW
8 Nov, 05:00	44,073 MW	43,167 MW
8 Nov, 06:00	44,436 MW	43,989 MW
8 Nov, 07:00	44,850 MW	44,974 MW
8 Nov, 08:00	46,599 MW	46,240 MW
8 Nov, 09:00	47,824 MW	47,716 MW
8 Nov, 10:00	48,958 MW	48,487 MW
8 Nov, 11:00	49,587 MW	49,243 MW
8 Nov, 12:00	50,010 MW	49,564 MW
8 Nov, 13:00	50,328 MW	49,905 MW
8 Nov, 14:00	50,423 MW	49,998 MW
8 Nov, 15:00	50,472 MW	50,043 MW
8 Nov, 16:00	50,530 MW	50,056 MW
8 Nov, 17:00	51,212 MW	51,016 MW
8 Nov, 18:00	51,677 MW	51,987 MW
8 Nov, 19:00	51,120 MW	51,592 MW
8 Nov, 20:00	50,224 MW	50,916 MW
8 Nov, 21:00	49,098 MW	49,960 MW
8 Nov, 22:00	47,818 MW	48,225 MW
8 Nov, 23:00	46,142 MW	46,226 MW
9 Nov, 00:00	44,550 MW	44,759 MW
9 Nov, 01:00	43,300 MW	43,616 MW
9 Nov, 02:00	42,775 MW	42,885 MW
9 Nov, 03:00	42,681 MW	42,965 MW
9 Nov, 04:00	43,349 MW	43,409 MW
9 Nov, 05:00	45,093 MW	45,166 MW
9 Nov, 06:00	47,542 MW	48,021 MW
9 Nov, 07:00	48,759 MW	49,271 MW
9 Nov, 08:00	49,518 MW	49,926 MW
9 Nov, 09:00	50,268 MW	50,638 MW
9 Nov, 10:00	50,851 MW	50,965 MW
9 Nov, 11:00	51,165 MW	51,432 MW
9 Nov, 12:00	51,112 MW	51,791 MW
9 Nov, 13:00	51,123 MW	52,100 MW
9 Nov, 14:00	51,221 MW	52,402 MW
9 Nov, 15:00	50,843 MW	52,643 MW
9 Nov, 16:00	51,189 MW	52,667 MW
9 Nov, 17:00	52,503 MW	53,219 MW
9 Nov, 18:00	53,531 MW	53,967 MW
9 Nov, 19:00	52,828 MW	53,361 MW
9 Nov, 20:00	51,767 MW	52,598 MW
9 Nov, 21:00	50,329 MW	51,268 MW
9 Nov, 22:00	48,095 MW	48,937 MW
9 Nov, 23:00	45,922 MW	46,858 MW
10 Nov, 00:00	44,440 MW	44,970 MW
10 Nov, 01:00	43,299 MW	43,798 MW
10 Nov, 02:00	42,627 MW	43,036 MW
10 Nov, 03:00	42,360 MW	43,077 MW
10 Nov, 04:00	43,161 MW	43,413 MW
10 Nov, 05:00	44,982 MW	45,095 MW
10 Nov, 06:00	47,534 MW	47,884 MW
10 Nov, 07:00	48,462 MW	48,965 MW
10 Nov, 08:00	49,392 MW	49,596 MW
10 Nov, 09:00	50,631 MW	50,275 MW
10 Nov, 10:00	51,381 MW	51,046 MW
10 Nov, 11:00	52,007 MW	51,712 MW
10 Nov, 12:00	52,823 MW	52,217 MW
10 Nov, 13:00	53,686 MW	52,861 MW
10 Nov, 14:00	53,841 MW	53,439 MW
10 Nov, 15:00	53,852 MW	53,722 MW
10 Nov, 16:00	53,540 MW	53,722 MW
10 Nov, 17:00	53,676 MW	54,223 MW
10 Nov, 18:00	53,852 MW	54,630 MW
10 Nov, 19:00	52,753 MW	54,005 MW
10 Nov, 20:00	51,624 MW	53,221 MW
10 Nov, 21:00	50,677 MW	52,009 MW
10 Nov, 22:00	48,850 MW	49,834 MW
10 Nov, 23:00	46,676 MW	47,615 MW
11 Nov, 00:00	45,030 MW	45,824 MW
11 Nov, 01:00	43,886 MW	44,415 MW
11 Nov, 02:00	43,246 MW	43,472 MW
11 Nov, 03:00	42,784 MW	43,296 MW
11 Nov, 04:00	43,071 MW	43,538 MW
11 Nov, 05:00	44,511 MW	45,102 MW
11 Nov, 06:00	47,027 MW	47,798 MW
11 Nov, 07:00	48,115 MW	48,867 MW
11 Nov, 08:00	49,307 MW	49,845 MW
11 Nov, 09:00	50,427 MW	50,860 MW
11 Nov, 10:00	51,441 MW	51,901 MW
11 Nov, 11:00	52,467 MW	52,988 MW
11 Nov, 12:00	53,608 MW	54,207 MW
11 Nov, 13:00	54,586 MW	55,389 MW
11 Nov, 14:00	55,577 MW	56,510 MW
11 Nov, 15:00	56,150 MW	56,962 MW
11 Nov, 16:00	55,599 MW	56,678 MW
11 Nov, 17:00	54,451 MW	56,602 MW
11 Nov, 18:00	54,187 MW	56,293 MW
11 Nov, 19:00	53,192 MW	55,220 MW
11 Nov, 20:00	51,807 MW	54,026 MW
11 Nov, 21:00	49,457 MW	52,387 MW
11 Nov, 22:00	47,029 MW	49,986 MW
11 Nov, 23:00	45,090 MW	47,608 MW
12 Nov, 00:00	44,448 MW	45,338 MW
12 Nov, 01:00	43,563 MW	43,954 MW
12 Nov, 02:00	42,830 MW	43,158 MW
12 Nov, 03:00	42,625 MW	43,026 MW
12 Nov, 04:00	43,241 MW	43,352 MW
12 Nov, 05:00	44,805 MW	44,849 MW
12 Nov, 06:00	47,454 MW	47,551 MW

Assumptions

Only hours with both a forecast and a positive demand reading count (719 of 720 hours in the window). Missing and zero values, and readings under 30% or over 3 times the grid's own median for the window, are treated as reporting faults and left out.
Error is (forecast minus reported demand) divided by reported demand; average error uses absolute values so high and low misses do not cancel. Bias keeps the sign and does cancel.
Reported demand is preliminary and may be revised. A 30 day window is a short sample and one heat wave or holiday can move these figures.
US figures are for the EIA balancing authority or region named on this page. US and European grids are ranked separately.

Cite this page

APA 7

World Power Monitor. (2026). ERCOT Demand Forecast Accuracy: Error, Bias and Worst Miss. https://worldpowermonitor.com/forecast-accuracy/ercot/

Plain text

World Power Monitor. ERCOT Demand Forecast Accuracy: Error, Bias and Worst Miss. Data as of 2026-11-12. Data from U.S. Energy Information Administration. https://worldpowermonitor.com/forecast-accuracy/ercot/

BibTeX

@misc{wpm_forecast_accuracy_ercot_2026,
  title = {{ERCOT Demand Forecast Accuracy: Error, Bias and Worst Miss}},
  author = {{World Power Monitor}},
  year = {2026},
  note = {Data as of 2026-11-12. Data from U.S. Energy Information Administration.},
  url = {https://worldpowermonitor.com/forecast-accuracy/ercot/}
}

Permalink: https://worldpowermonitor.com/forecast-accuracy/ercot/

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ERCOT Demand Forecast Accuracy: Error, Bias and Worst Miss, 13 October to 12 November 2026

Key Facts

Forecast Error at a Glance

Forecast and Reported Demand, Last 7 Days

Assumptions

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