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Built 2026-11-05 (5 November 2026)

ISO-NE Demand Forecast Accuracy: Error, Bias and Worst Miss, 6 October to 5 November 2026

The day-ahead demand forecast for ISO-NE was off by 3.6% on average (mean absolute percentage error) over 719 hours from 6 October to 5 November 2026, and 70% of hours landed within 5% of the reading. Its bias was -3.1%: it ran low on average, an under forecast. The largest miss was 1,662 MW (17.6%) too low at 23 Oct 2026, 11:00 EDT (UTC-04:00). Dates and times are local (America/New_York).

Key Facts

  • The day-ahead demand forecast for ISO-NE was off by 3.6% on average (mean absolute percentage error) over 719 hours from 6 October to 5 November 2026, and 70% of hours landed within 5% of the reading. Its bias was -3.1%: it ran low on average, an under forecast. The largest miss was 1,662 MW (17.6%) too low at 23 Oct 2026, 11:00 EDT (UTC-04:00).
  • Across 53 US grids ranked by average error over their own latest 30 day windows, ISO-NE came 26 (1 is the smallest error).
  • On average the forecast differed from reported demand by 374 MW, against average demand of 11,394 MW.
  • The forecast was above reported demand in 22% of compared hours.

Forecast Error at a Glance

719 hours from 6 October to 5 November 2026
Average error3.6%
Bias-3.1%
Hours within 5%70%
Worst miss1,662 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (-318 MW per hour on average): the forecast ran low on average, an under forecast. The worst miss was 1,662 MW (17.6%) too low at 23 Oct 2026, 11:00 EDT (UTC-04:00): forecast 7,760 MW, reported 9,422 MW.

Source: U.S. Energy Information Administration (EIA). (US Government work, public domain) Data as of 2026-11-05. 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 5 Nov 2026, 08:00 EST (UTC-05:00)
ISO-NE day-ahead demand forecast and reported demand by hour Hourly reported demand and the day-ahead forecast for ISO-NE over the last 7 days of the window, to 5 Nov 2026, 08:00 EST (UTC-05:00). Gaps are hours with a missing, zero or implausible report. 0 3,750 7,500 11,250 15,000 29 Oct, 10:0030 Oct, 10:0031 Oct, 10:001 Nov, 09:002 Nov, 09:003 Nov, 09:004 Nov, 09:00
Hourly reported demand and the day-ahead forecast for ISO-NE over the last 7 days of the window, to 5 Nov 2026, 08:00 EST (UTC-05:00). Gaps are hours with a missing, zero or implausible report.
Data to 2026-11-05
Show the data table (168 rows)
Local hourReported demandDay-ahead forecast
29 Oct, 10:009,834 MW9,540 MW
29 Oct, 11:009,357 MW8,850 MW
29 Oct, 12:009,030 MW8,520 MW
29 Oct, 13:009,090 MW8,700 MW
29 Oct, 14:009,678 MW9,340 MW
29 Oct, 15:0010,712 MW10,450 MW
29 Oct, 16:0012,161 MW12,120 MW
29 Oct, 17:0013,562 MW13,500 MW
29 Oct, 18:0014,062 MW14,150 MW
29 Oct, 19:0013,812 MW13,840 MW
29 Oct, 20:0013,314 MW13,320 MW
29 Oct, 21:0012,613 MW12,540 MW
29 Oct, 22:0011,702 MW11,570 MW
29 Oct, 23:0010,981 MW10,670 MW
30 Oct, 00:0010,414 MW10,170 MW
30 Oct, 01:0010,241 MW9,730 MW
30 Oct, 02:0010,098 MW9,540 MW
30 Oct, 03:0010,025 MW9,490 MW
30 Oct, 04:0010,212 MW9,720 MW
30 Oct, 05:0010,778 MW10,480 MW
30 Oct, 06:0011,635 MW11,930 MW
30 Oct, 07:0012,552 MW12,720 MW
30 Oct, 08:0012,216 MW11,980 MW
30 Oct, 09:0010,956 MW10,820 MW
30 Oct, 10:0010,283 MW9,610 MW
30 Oct, 11:009,693 MW8,930 MW
30 Oct, 12:009,640 MW8,730 MW
30 Oct, 13:009,734 MW8,970 MW
30 Oct, 14:0010,053 MW9,660 MW
30 Oct, 15:0010,839 MW10,610 MW
30 Oct, 16:0012,001 MW11,970 MW
30 Oct, 17:0013,116 MW13,230 MW
30 Oct, 18:0013,449 MW13,600 MW
30 Oct, 19:0013,120 MW13,370 MW
30 Oct, 20:0012,682 MW12,890 MW
30 Oct, 21:0012,124 MW12,290 MW
30 Oct, 22:0011,393 MW11,550 MW
30 Oct, 23:0010,737 MW10,790 MW
31 Oct, 00:0010,390 MW10,210 MW
31 Oct, 01:0010,136 MW9,840 MW
31 Oct, 02:009,991 MW9,630 MW
31 Oct, 03:0010,042 MW9,560 MW
31 Oct, 04:0010,086 MW9,700 MW
31 Oct, 05:0010,297 MW10,090 MW
31 Oct, 06:0010,596 MW10,820 MW
31 Oct, 07:0011,287 MW11,390 MW
31 Oct, 08:0010,997 MW10,710 MW
31 Oct, 09:0010,038 MW9,450 MW
31 Oct, 10:009,272 MW8,320 MW
31 Oct, 11:008,566 MW7,630 MW
31 Oct, 12:008,499 MW7,370 MW
31 Oct, 13:008,640 MW7,540 MW
31 Oct, 14:008,821 MW8,280 MW
31 Oct, 15:0010,031 MW9,470 MW
31 Oct, 16:0011,516 MW11,160 MW
31 Oct, 17:0012,559 MW12,660 MW
31 Oct, 18:0012,768 MW13,300 MW
31 Oct, 19:0012,561 MW13,170 MW
31 Oct, 20:0012,413 MW12,880 MW
31 Oct, 21:0012,080 MW12,410 MW
31 Oct, 22:0011,577 MW11,760 MW
31 Oct, 23:0011,036 MW11,110 MW
1 Nov, 00:0010,936 MW10,570 MW
1 Nov, 01:0010,685 MW10,300 MW
1 Nov, 01:0010,465 MW10,300 MW
1 Nov, 02:0010,571 MW10,030 MW
1 Nov, 03:0010,660 MW10,100 MW
1 Nov, 04:0010,312 MW10,290 MW
1 Nov, 05:0010,706 MW10,730 MW
1 Nov, 06:0011,331 MW11,350 MW
1 Nov, 07:0011,033 MW11,020 MW
1 Nov, 08:009,851 MW9,590 MW
1 Nov, 09:008,965 MW8,410 MW
1 Nov, 10:008,526 MW7,690 MW
1 Nov, 11:008,521 MW7,480 MW
1 Nov, 12:008,703 MW7,640 MW
1 Nov, 13:009,220 MW8,320 MW
1 Nov, 14:0010,237 MW9,660 MW
1 Nov, 15:0011,639 MW11,690 MW
1 Nov, 16:0013,362 MW13,300 MW
1 Nov, 17:0014,202 MW13,980 MW
1 Nov, 18:0014,004 MW14,000 MW
1 Nov, 19:0013,598 MW13,540 MW
1 Nov, 20:0013,079 MW12,990 MW
1 Nov, 21:0012,196 MW12,260 MW
1 Nov, 22:0011,437 MW11,420 MW
1 Nov, 23:0011,156 MW10,650 MW
2 Nov, 00:0010,804 MW10,120 MW
2 Nov, 01:0010,585 MW9,810 MW
2 Nov, 02:0010,684 MW9,630 MW
2 Nov, 03:0010,496 MW9,680 MW
2 Nov, 04:0010,824 MW10,070 MW
2 Nov, 05:0011,462 MW10,950 MW
2 Nov, 06:0012,612 MW12,510 MW
2 Nov, 07:0012,549 MW12,470 MW
2 Nov, 08:0011,347 MW11,170 MW
2 Nov, 09:0010,464 MW10,110 MW
2 Nov, 10:0010,004 MW9,470 MW
2 Nov, 11:009,753 MW9,420 MW
2 Nov, 12:009,877 MW9,620 MW
2 Nov, 13:0010,393 MW10,260 MW
2 Nov, 14:0011,125 MW11,060 MW
2 Nov, 15:0012,471 MW12,240 MW
2 Nov, 16:0013,749 MW13,650 MW
2 Nov, 17:0014,500 MW14,450 MW
2 Nov, 18:0014,257 MW14,360 MW
2 Nov, 19:0013,758 MW13,860 MW
2 Nov, 20:0013,177 MW13,250 MW
2 Nov, 21:0012,315 MW12,390 MW
2 Nov, 22:0011,579 MW11,400 MW
2 Nov, 23:0011,057 MW10,580 MW
3 Nov, 00:0010,600 MW9,990 MW
3 Nov, 01:0010,234 MW9,610 MW
3 Nov, 02:0010,027 MW9,410 MW
3 Nov, 03:0010,005 MW9,410 MW
3 Nov, 04:0010,100 MW9,730 MW
3 Nov, 05:0010,874 MW10,600 MW
3 Nov, 06:0012,089 MW11,810 MW
3 Nov, 07:0012,296 MW11,990 MW
3 Nov, 08:0011,882 MW11,460 MW
3 Nov, 09:0011,461 MW11,010 MW
3 Nov, 10:0011,298 MW10,740 MW
3 Nov, 11:0011,029 MW10,390 MW
3 Nov, 12:0010,991 MW10,380 MW
3 Nov, 13:0011,474 MW11,020 MW
3 Nov, 14:0012,126 MW12,070 MW
3 Nov, 15:0012,884 MW12,920 MW
3 Nov, 16:0013,637 MW13,780 MW
3 Nov, 17:0014,291 MW14,500 MW
3 Nov, 18:0014,108 MW14,290 MW
3 Nov, 19:0013,708 MW13,800 MW
3 Nov, 20:0013,104 MW13,150 MW
3 Nov, 21:0012,303 MW12,320 MW
3 Nov, 22:0011,350 MW11,350 MW
3 Nov, 23:0010,541 MW10,520 MW
4 Nov, 00:0010,536 MW9,950 MW
4 Nov, 01:0010,180 MW9,540 MW
4 Nov, 02:0010,188 MW9,320 MW
4 Nov, 03:0010,166 MW9,300 MW
4 Nov, 04:0010,427 MW9,590 MW
4 Nov, 05:0010,926 MW10,380 MW
4 Nov, 06:0011,844 MW11,790 MW
4 Nov, 07:0011,872 MW11,890 MW
4 Nov, 08:0011,016 MW10,870 MW
4 Nov, 09:0010,196 MW9,850 MW
4 Nov, 10:009,959 MW9,210 MW
4 Nov, 11:009,930 MW9,140 MW
4 Nov, 12:0010,165 MW9,380 MW
4 Nov, 13:0010,759 MW10,130 MW
4 Nov, 14:0011,508 MW11,080 MW
4 Nov, 15:0012,750 MW12,550 MW
4 Nov, 16:0013,863 MW13,950 MW
4 Nov, 17:0014,473 MW14,700 MW
4 Nov, 18:0014,183 MW14,410 MW
4 Nov, 19:0013,786 MW13,840 MW
4 Nov, 20:0013,144 MW13,260 MW
4 Nov, 21:0012,379 MW12,430 MW
4 Nov, 22:0011,420 MW11,440 MW
4 Nov, 23:0010,846 MW10,620 MW
5 Nov, 00:0010,426 MW10,090 MW
5 Nov, 01:0010,599 MW9,730 MW
5 Nov, 02:0010,667 MW9,490 MW
5 Nov, 03:0010,603 MW9,480 MW
5 Nov, 04:0010,254 MW9,840 MW
5 Nov, 05:0010,986 MW10,700 MW
5 Nov, 06:0012,018 MW12,030 MW
5 Nov, 07:0012,389 MW12,540 MW
5 Nov, 08:0012,098 MW12,360 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). ISO-NE Demand Forecast Accuracy: Error, Bias and Worst Miss. https://worldpowermonitor.com/forecast-accuracy/iso-ne/

Plain text

World Power Monitor. ISO-NE Demand Forecast Accuracy: Error, Bias and Worst Miss. Data as of 2026-11-05. Data from U.S. Energy Information Administration. https://worldpowermonitor.com/forecast-accuracy/iso-ne/

BibTeX 
@misc{wpm_forecast_accuracy_iso_ne_2026,
  title = {{ISO-NE Demand Forecast Accuracy: Error, Bias and Worst Miss}},
  author = {{World Power Monitor}},
  year = {2026},
  note = {Data as of 2026-11-05. Data from U.S. Energy Information Administration.},
  url = {https://worldpowermonitor.com/forecast-accuracy/iso-ne/}
}

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