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

The day-ahead demand forecast for SPP was off by 5.4% on average (mean absolute percentage error) over 695 hours from 13 October to 12 November 2026, and 61% of hours landed within 5% of the reading. Its bias was +5.1%: it ran high on average, an over forecast. The largest miss was 6,115 MW (17.7%) too high at 2 Nov 2026, 15:00 CST (UTC-06:00). Dates and times are local (America/Chicago).

Key Facts

The day-ahead demand forecast for SPP was off by 5.4% on average (mean absolute percentage error) over 695 hours from 13 October to 12 November 2026, and 61% of hours landed within 5% of the reading. Its bias was +5.1%: it ran high on average, an over forecast. The largest miss was 6,115 MW (17.7%) too high at 2 Nov 2026, 15:00 CST (UTC-06:00).
Across 53 US grids ranked by average error over their own latest 30 day windows, SPP came 33 (1 is the smallest error).
On average the forecast differed from reported demand by 1,669 MW, against average demand of 31,092 MW.
The forecast was above reported demand in 80% of compared hours.

Forecast Error at a Glance

695 hours from 13 October to 12 November 2026

Average error5.4%

Bias+5.1%

Hours within 5%61%

Worst miss6,115 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (+1,567 MW per hour on average): the forecast ran high on average, an over forecast. The worst miss was 6,115 MW (17.7%) too high at 2 Nov 2026, 15:00 CST (UTC-06:00): forecast 40,748 MW, reported 34,633 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 SPP 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	31,862 MW	35,872 MW
5 Nov, 08:00	32,018 MW	36,220 MW
5 Nov, 09:00	32,015 MW	35,989 MW
5 Nov, 10:00	32,252 MW	35,837 MW
5 Nov, 11:00	32,223 MW	35,688 MW
5 Nov, 12:00	32,381 MW	35,610 MW
5 Nov, 13:00	32,543 MW	35,647 MW
5 Nov, 14:00	32,486 MW	35,585 MW
5 Nov, 15:00	32,252 MW	35,464 MW
5 Nov, 16:00	32,309 MW	35,611 MW
5 Nov, 17:00	32,716 MW	36,064 MW
5 Nov, 18:00	32,908 MW	36,441 MW
5 Nov, 19:00	32,645 MW	36,317 MW
5 Nov, 20:00	32,164 MW	36,091 MW
5 Nov, 21:00	31,373 MW	35,580 MW
5 Nov, 22:00	30,228 MW	34,803 MW
5 Nov, 23:00	29,187 MW	33,942 MW
6 Nov, 00:00	28,510 MW	28,537 MW
6 Nov, 01:00	28,142 MW	28,256 MW
6 Nov, 02:00	27,962 MW	28,112 MW
6 Nov, 03:00	28,000 MW	28,128 MW
6 Nov, 04:00	28,379 MW	28,478 MW
6 Nov, 05:00	29,487 MW	29,498 MW
6 Nov, 06:00	31,289 MW	31,222 MW
6 Nov, 07:00	32,288 MW	32,280 MW
6 Nov, 08:00	32,579 MW	32,577 MW
6 Nov, 09:00	32,648 MW	32,726 MW
6 Nov, 10:00	32,700 MW	32,755 MW
6 Nov, 11:00	32,636 MW	32,582 MW
6 Nov, 12:00	32,470 MW	32,496 MW
6 Nov, 13:00	32,411 MW	32,256 MW
6 Nov, 14:00	32,171 MW	31,843 MW
6 Nov, 15:00	32,033 MW	31,507 MW
6 Nov, 16:00	32,229 MW	31,471 MW
6 Nov, 17:00	32,746 MW	31,612 MW
6 Nov, 18:00	32,798 MW	31,843 MW
6 Nov, 19:00	32,350 MW	31,647 MW
6 Nov, 20:00	31,990 MW	31,476 MW
6 Nov, 21:00	31,438 MW	31,047 MW
6 Nov, 22:00	30,680 MW	30,535 MW
6 Nov, 23:00	29,802 MW	29,910 MW
7 Nov, 00:00	29,051 MW	32,667 MW
7 Nov, 01:00	28,621 MW	32,468 MW
7 Nov, 02:00	28,410 MW	32,313 MW
7 Nov, 03:00	28,285 MW	32,410 MW
7 Nov, 04:00	28,456 MW	32,704 MW
7 Nov, 05:00	29,012 MW	33,383 MW
7 Nov, 06:00	29,814 MW	34,176 MW
7 Nov, 07:00	30,522 MW	34,535 MW
7 Nov, 08:00	31,074 MW	35,093 MW
7 Nov, 09:00	31,124 MW	35,216 MW
7 Nov, 10:00	30,850 MW	35,047 MW
7 Nov, 11:00	30,559 MW	34,605 MW
7 Nov, 12:00	30,250 MW	34,383 MW
7 Nov, 13:00	30,056 MW	34,076 MW
7 Nov, 14:00	29,879 MW	33,607 MW
7 Nov, 15:00	29,911 MW	33,283 MW
7 Nov, 16:00	30,278 MW	33,385 MW
7 Nov, 17:00	31,119 MW	34,037 MW
7 Nov, 18:00	31,446 MW	34,471 MW
7 Nov, 19:00	31,136 MW	34,458 MW
7 Nov, 20:00	30,837 MW	34,468 MW
7 Nov, 21:00	30,320 MW	34,213 MW
7 Nov, 22:00	29,649 MW	33,916 MW
7 Nov, 23:00	28,979 MW	33,352 MW
8 Nov, 00:00	28,463 MW	28,642 MW
8 Nov, 01:00	28,191 MW	28,354 MW
8 Nov, 02:00	27,992 MW	28,194 MW
8 Nov, 03:00	27,913 MW	28,225 MW
8 Nov, 04:00	28,066 MW	28,385 MW
8 Nov, 05:00	28,454 MW	28,828 MW
8 Nov, 06:00	29,126 MW	29,507 MW
8 Nov, 07:00	29,620 MW	29,956 MW
8 Nov, 08:00	29,852 MW	30,352 MW
8 Nov, 09:00	29,772 MW	30,316 MW
8 Nov, 10:00	29,730 MW	30,198 MW
8 Nov, 11:00	29,651 MW	30,113 MW
8 Nov, 12:00	29,656 MW	30,124 MW
8 Nov, 13:00	29,707 MW	29,990 MW
8 Nov, 14:00	29,817 MW	29,750 MW
8 Nov, 15:00	30,104 MW	29,653 MW
8 Nov, 16:00	30,704 MW	29,961 MW
8 Nov, 17:00	31,514 MW	30,873 MW
8 Nov, 18:00	31,688 MW	31,260 MW
8 Nov, 19:00	31,283 MW	31,191 MW
8 Nov, 20:00	30,766 MW	31,111 MW
8 Nov, 21:00	29,965 MW	30,547 MW
8 Nov, 22:00	28,984 MW	29,583 MW
8 Nov, 23:00	28,119 MW	28,751 MW
9 Nov, 00:00	27,602 MW	31,474 MW
9 Nov, 01:00	27,348 MW	31,177 MW
9 Nov, 02:00	27,320 MW	31,164 MW
9 Nov, 03:00	27,502 MW	31,302 MW
9 Nov, 04:00	28,163 MW	31,840 MW
9 Nov, 05:00	29,587 MW	33,133 MW
9 Nov, 06:00	31,673 MW	35,084 MW
9 Nov, 07:00	32,669 MW	36,221 MW
9 Nov, 08:00	32,458 MW	36,344 MW
9 Nov, 09:00	32,071 MW	35,828 MW
9 Nov, 10:00	31,884 MW	35,382 MW
9 Nov, 11:00	31,929 MW	35,427 MW
9 Nov, 12:00	31,910 MW	35,546 MW
9 Nov, 13:00	32,017 MW	35,806 MW
9 Nov, 14:00	32,062 MW	35,779 MW
9 Nov, 15:00	32,118 MW	35,715 MW
9 Nov, 16:00	32,162 MW	35,753 MW
9 Nov, 17:00	32,643 MW	36,336 MW
9 Nov, 18:00	32,901 MW	36,805 MW
9 Nov, 19:00	32,479 MW	36,446 MW
9 Nov, 20:00	31,945 MW	36,097 MW
9 Nov, 21:00	31,118 MW	35,336 MW
9 Nov, 22:00	29,931 MW	34,229 MW
9 Nov, 23:00	28,883 MW	32,966 MW
10 Nov, 00:00	28,267 MW	n/a
10 Nov, 01:00	27,885 MW	n/a
10 Nov, 02:00	27,724 MW	n/a
10 Nov, 03:00	27,753 MW	n/a
10 Nov, 04:00	28,151 MW	n/a
10 Nov, 05:00	29,284 MW	n/a
10 Nov, 06:00	31,202 MW	n/a
10 Nov, 07:00	32,161 MW	n/a
10 Nov, 08:00	32,073 MW	n/a
10 Nov, 09:00	31,871 MW	n/a
10 Nov, 10:00	31,788 MW	n/a
10 Nov, 11:00	31,893 MW	n/a
10 Nov, 12:00	32,084 MW	n/a
10 Nov, 13:00	32,355 MW	n/a
10 Nov, 14:00	32,537 MW	n/a
10 Nov, 15:00	32,628 MW	n/a
10 Nov, 16:00	32,741 MW	n/a
10 Nov, 17:00	33,127 MW	n/a
10 Nov, 18:00	33,111 MW	n/a
10 Nov, 19:00	32,612 MW	n/a
10 Nov, 20:00	32,095 MW	n/a
10 Nov, 21:00	31,235 MW	n/a
10 Nov, 22:00	30,109 MW	n/a
10 Nov, 23:00	29,090 MW	n/a
11 Nov, 00:00	28,196 MW	31,713 MW
11 Nov, 01:00	27,717 MW	31,122 MW
11 Nov, 02:00	27,491 MW	30,932 MW
11 Nov, 03:00	27,617 MW	30,840 MW
11 Nov, 04:00	27,974 MW	31,087 MW
11 Nov, 05:00	29,037 MW	31,590 MW
11 Nov, 06:00	30,849 MW	32,688 MW
11 Nov, 07:00	31,757 MW	33,195 MW
11 Nov, 08:00	31,835 MW	33,460 MW
11 Nov, 09:00	31,665 MW	33,453 MW
11 Nov, 10:00	31,765 MW	33,475 MW
11 Nov, 11:00	32,005 MW	33,859 MW
11 Nov, 12:00	32,235 MW	34,201 MW
11 Nov, 13:00	32,497 MW	34,529 MW
11 Nov, 14:00	32,517 MW	34,688 MW
11 Nov, 15:00	32,452 MW	34,759 MW
11 Nov, 16:00	32,595 MW	35,004 MW
11 Nov, 17:00	33,085 MW	35,741 MW
11 Nov, 18:00	33,232 MW	36,074 MW
11 Nov, 19:00	32,600 MW	35,882 MW
11 Nov, 20:00	32,118 MW	35,575 MW
11 Nov, 21:00	31,290 MW	34,702 MW
11 Nov, 22:00	30,177 MW	33,825 MW
11 Nov, 23:00	29,099 MW	33,028 MW
12 Nov, 00:00	28,443 MW	31,753 MW
12 Nov, 01:00	28,174 MW	31,308 MW
12 Nov, 02:00	27,959 MW	31,189 MW
12 Nov, 03:00	27,970 MW	31,077 MW
12 Nov, 04:00	28,426 MW	31,644 MW
12 Nov, 05:00	29,544 MW	33,173 MW
12 Nov, 06:00	31,434 MW	35,607 MW

Assumptions

Only hours with both a forecast and a positive demand reading count (695 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). SPP Demand Forecast Accuracy: Error, Bias and Worst Miss. https://worldpowermonitor.com/forecast-accuracy/spp/

Plain text

World Power Monitor. SPP 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/spp/

BibTeX

@misc{wpm_forecast_accuracy_spp_2026,
  title = {{SPP 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/spp/}
}

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

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SPP 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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