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Built 2026-11-12 (12 November 2026)

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

The day-ahead demand forecast for NYISO was off by 2.9% on average (mean absolute percentage error) over 719 hours from 13 October to 12 November 2026, and 84% of hours landed within 5% of the reading. Its bias was -2.8%: it ran low on average, an under forecast. The largest miss was 1,280 MW (9.1%) too low at 25 Oct 2026, 08:00 EDT (UTC-04:00). Dates and times are local (America/New_York).

Key Facts

  • The day-ahead demand forecast for NYISO was off by 2.9% on average (mean absolute percentage error) over 719 hours from 13 October to 12 November 2026, and 84% of hours landed within 5% of the reading. Its bias was -2.8%: it ran low on average, an under forecast. The largest miss was 1,280 MW (9.1%) too low at 25 Oct 2026, 08:00 EDT (UTC-04:00).
  • Across 53 US grids ranked by average error over their own latest 30 day windows, NYISO came 15 (1 is the smallest error).
  • On average the forecast differed from reported demand by 426 MW, against average demand of 14,809 MW.
  • The forecast was above reported demand in 7% of compared hours.

Forecast Error at a Glance

719 hours from 13 October to 12 November 2026
Average error2.9%
Bias-2.8%
Hours within 5%84%
Worst miss1,280 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (-406 MW per hour on average): the forecast ran low on average, an under forecast. The worst miss was 1,280 MW (9.1%) too low at 25 Oct 2026, 08:00 EDT (UTC-04:00): forecast 12,830 MW, reported 14,110 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, 07:00 EST (UTC-05:00)
NYISO day-ahead demand forecast and reported demand by hour Hourly reported demand and the day-ahead forecast for NYISO over the last 7 days of the window, to 12 Nov 2026, 07:00 EST (UTC-05:00). Gaps are hours with a missing, zero or implausible report. 0 5,000 10,000 15,000 20,000 5 Nov, 08:006 Nov, 08:007 Nov, 08:008 Nov, 08:009 Nov, 08:0010 Nov, 08:0011 Nov, 08:00
Hourly reported demand and the day-ahead forecast for NYISO over the last 7 days of the window, to 12 Nov 2026, 07:00 EST (UTC-05:00). Gaps are hours with a missing, zero or implausible report.
Data to 2026-11-12
Show the data table (168 rows)
Local hourReported demandDay-ahead forecast
5 Nov, 08:0016,451 MW16,160 MW
5 Nov, 09:0016,439 MW16,086 MW
5 Nov, 10:0016,523 MW15,937 MW
5 Nov, 11:0016,519 MW15,893 MW
5 Nov, 12:0016,480 MW15,792 MW
5 Nov, 13:0016,448 MW15,780 MW
5 Nov, 14:0016,518 MW15,849 MW
5 Nov, 15:0017,078 MW16,413 MW
5 Nov, 16:0017,903 MW17,354 MW
5 Nov, 17:0018,501 MW18,070 MW
5 Nov, 18:0018,255 MW17,794 MW
5 Nov, 19:0017,796 MW17,265 MW
5 Nov, 20:0017,212 MW16,684 MW
5 Nov, 21:0016,478 MW16,007 MW
5 Nov, 22:0015,553 MW15,177 MW
5 Nov, 23:0014,652 MW14,330 MW
6 Nov, 00:0013,986 MW13,693 MW
6 Nov, 01:0013,468 MW13,214 MW
6 Nov, 02:0013,127 MW12,890 MW
6 Nov, 03:0012,991 MW12,759 MW
6 Nov, 04:0013,101 MW12,923 MW
6 Nov, 05:0013,772 MW13,619 MW
6 Nov, 06:0015,132 MW14,868 MW
6 Nov, 07:0016,172 MW15,700 MW
6 Nov, 08:0016,543 MW15,846 MW
6 Nov, 09:0016,378 MW15,675 MW
6 Nov, 10:0016,250 MW15,520 MW
6 Nov, 11:0016,184 MW15,443 MW
6 Nov, 12:0016,467 MW15,407 MW
6 Nov, 13:0016,721 MW15,577 MW
6 Nov, 14:0016,783 MW15,810 MW
6 Nov, 15:0017,019 MW16,363 MW
6 Nov, 16:0017,500 MW16,981 MW
6 Nov, 17:0017,805 MW17,432 MW
6 Nov, 18:0017,443 MW17,034 MW
6 Nov, 19:0017,015 MW16,554 MW
6 Nov, 20:0016,479 MW16,039 MW
6 Nov, 21:0015,796 MW15,432 MW
6 Nov, 22:0015,012 MW14,687 MW
6 Nov, 23:0014,279 MW13,928 MW
7 Nov, 00:0013,674 MW13,451 MW
7 Nov, 01:0013,176 MW12,937 MW
7 Nov, 02:0012,817 MW12,612 MW
7 Nov, 03:0012,648 MW12,425 MW
7 Nov, 04:0012,612 MW12,444 MW
7 Nov, 05:0012,818 MW12,696 MW
7 Nov, 06:0013,354 MW13,139 MW
7 Nov, 07:0013,809 MW13,356 MW
7 Nov, 08:0014,056 MW13,577 MW
7 Nov, 09:0014,181 MW13,501 MW
7 Nov, 10:0014,443 MW13,500 MW
7 Nov, 11:0014,687 MW13,602 MW
7 Nov, 12:0014,830 MW13,698 MW
7 Nov, 13:0014,736 MW13,792 MW
7 Nov, 14:0014,888 MW14,110 MW
7 Nov, 15:0015,317 MW14,724 MW
7 Nov, 16:0015,923 MW15,730 MW
7 Nov, 17:0016,527 MW16,559 MW
7 Nov, 18:0016,396 MW16,354 MW
7 Nov, 19:0016,106 MW16,041 MW
7 Nov, 20:0015,763 MW15,571 MW
7 Nov, 21:0015,291 MW15,087 MW
7 Nov, 22:0014,644 MW14,481 MW
7 Nov, 23:0014,042 MW13,822 MW
8 Nov, 00:0013,545 MW13,361 MW
8 Nov, 01:0013,114 MW12,820 MW
8 Nov, 02:0012,784 MW12,541 MW
8 Nov, 03:0012,568 MW12,391 MW
8 Nov, 04:0012,546 MW12,412 MW
8 Nov, 05:0012,770 MW12,626 MW
8 Nov, 06:0013,212 MW12,975 MW
8 Nov, 07:0013,542 MW12,944 MW
8 Nov, 08:0013,608 MW12,868 MW
8 Nov, 09:0013,469 MW12,532 MW
8 Nov, 10:0013,206 MW12,338 MW
8 Nov, 11:0012,861 MW12,289 MW
8 Nov, 12:0012,633 MW12,323 MW
8 Nov, 13:0012,777 MW12,416 MW
8 Nov, 14:0013,738 MW12,915 MW
8 Nov, 15:0014,915 MW14,009 MW
8 Nov, 16:0015,932 MW15,510 MW
8 Nov, 17:0016,797 MW16,675 MW
8 Nov, 18:0016,717 MW16,627 MW
8 Nov, 19:0016,465 MW16,277 MW
8 Nov, 20:0016,037 MW15,798 MW
8 Nov, 21:0015,410 MW15,148 MW
8 Nov, 22:0014,646 MW14,376 MW
8 Nov, 23:0013,854 MW13,638 MW
9 Nov, 00:0013,304 MW13,156 MW
9 Nov, 01:0012,958 MW12,778 MW
9 Nov, 02:0012,700 MW12,536 MW
9 Nov, 03:0012,609 MW12,492 MW
9 Nov, 04:0012,863 MW12,740 MW
9 Nov, 05:0013,696 MW13,528 MW
9 Nov, 06:0015,067 MW14,839 MW
9 Nov, 07:0016,071 MW15,596 MW
9 Nov, 08:0016,476 MW15,681 MW
9 Nov, 09:0016,339 MW15,391 MW
9 Nov, 10:0016,235 MW15,185 MW
9 Nov, 11:0016,194 MW15,122 MW
9 Nov, 12:0016,130 MW15,145 MW
9 Nov, 13:0016,256 MW15,349 MW
9 Nov, 14:0016,406 MW15,719 MW
9 Nov, 15:0016,825 MW16,342 MW
9 Nov, 16:0017,563 MW17,100 MW
9 Nov, 17:0018,231 MW17,927 MW
9 Nov, 18:0018,077 MW17,752 MW
9 Nov, 19:0017,689 MW17,386 MW
9 Nov, 20:0017,124 MW16,841 MW
9 Nov, 21:0016,315 MW16,020 MW
9 Nov, 22:0015,392 MW15,061 MW
9 Nov, 23:0014,449 MW14,204 MW
10 Nov, 00:0013,801 MW13,752 MW
10 Nov, 01:0013,340 MW13,332 MW
10 Nov, 02:0013,066 MW13,060 MW
10 Nov, 03:0012,955 MW12,986 MW
10 Nov, 04:0013,159 MW13,208 MW
10 Nov, 05:0013,965 MW13,971 MW
10 Nov, 06:0015,341 MW15,260 MW
10 Nov, 07:0016,059 MW15,904 MW
10 Nov, 08:0015,934 MW15,769 MW
10 Nov, 09:0015,444 MW15,248 MW
10 Nov, 10:0014,647 MW14,816 MW
10 Nov, 11:0014,222 MW14,559 MW
10 Nov, 12:0014,124 MW14,357 MW
10 Nov, 13:0014,248 MW14,443 MW
10 Nov, 14:0014,757 MW14,834 MW
10 Nov, 15:0015,811 MW15,669 MW
10 Nov, 16:0016,999 MW16,752 MW
10 Nov, 17:0017,741 MW17,726 MW
10 Nov, 18:0017,632 MW17,654 MW
10 Nov, 19:0017,259 MW17,284 MW
10 Nov, 20:0016,752 MW16,762 MW
10 Nov, 21:0016,038 MW15,963 MW
10 Nov, 22:0015,166 MW15,030 MW
10 Nov, 23:0014,294 MW14,187 MW
11 Nov, 00:0013,711 MW13,616 MW
11 Nov, 01:0013,237 MW13,175 MW
11 Nov, 02:0012,953 MW12,880 MW
11 Nov, 03:0012,859 MW12,766 MW
11 Nov, 04:0013,057 MW12,934 MW
11 Nov, 05:0013,729 MW13,568 MW
11 Nov, 06:0014,789 MW14,471 MW
11 Nov, 07:0015,277 MW14,705 MW
11 Nov, 08:0014,716 MW14,571 MW
11 Nov, 09:0014,129 MW14,225 MW
11 Nov, 10:0014,022 MW13,960 MW
11 Nov, 11:0014,150 MW14,002 MW
11 Nov, 12:0014,414 MW14,251 MW
11 Nov, 13:0014,908 MW14,802 MW
11 Nov, 14:0015,520 MW15,424 MW
11 Nov, 15:0016,212 MW16,199 MW
11 Nov, 16:0017,095 MW17,005 MW
11 Nov, 17:0017,802 MW17,771 MW
11 Nov, 18:0017,579 MW17,591 MW
11 Nov, 19:0017,239 MW17,248 MW
11 Nov, 20:0016,722 MW16,724 MW
11 Nov, 21:0015,985 MW15,910 MW
11 Nov, 22:0015,089 MW14,980 MW
11 Nov, 23:0014,266 MW14,141 MW
12 Nov, 00:0013,655 MW13,472 MW
12 Nov, 01:0013,191 MW13,043 MW
12 Nov, 02:0012,903 MW12,765 MW
12 Nov, 03:0012,787 MW12,657 MW
12 Nov, 04:0013,029 MW12,846 MW
12 Nov, 05:0013,783 MW13,581 MW
12 Nov, 06:0015,162 MW14,906 MW
12 Nov, 07:0016,078 MW15,876 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). NYISO Demand Forecast Accuracy: Error, Bias and Worst Miss. https://worldpowermonitor.com/forecast-accuracy/nyiso/

Plain text

World Power Monitor. NYISO 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/nyiso/

BibTeX 
@misc{wpm_forecast_accuracy_nyiso_2026,
  title = {{NYISO 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/nyiso/}
}

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