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Built 2026-11-05 (5 November 2026)

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

The day-ahead demand forecast for NYISO was off by 3.1% on average (mean absolute percentage error) over 719 hours from 6 October to 5 November 2026, and 84% of hours landed within 5% of the reading. Its bias was -2.9%: 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 3.1% on average (mean absolute percentage error) over 719 hours from 6 October to 5 November 2026, and 84% of hours landed within 5% of the reading. Its bias was -2.9%: 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 18 (1 is the smallest error).
  • On average the forecast differed from reported demand by 440 MW, against average demand of 14,658 MW.
  • The forecast was above reported demand in 6% of compared hours.

Forecast Error at a Glance

719 hours from 6 October to 5 November 2026
Average error3.1%
Bias-2.9%
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 (-424 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 2026-11-05. 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)
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 5 Nov 2026, 08:00 EST (UTC-05:00). Gaps are hours with a missing, zero or implausible report. 0 5,000 10,000 15,000 20,000 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 NYISO 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, 10:0014,160 MW13,367 MW
29 Oct, 11:0013,857 MW12,983 MW
29 Oct, 12:0013,701 MW12,811 MW
29 Oct, 13:0013,660 MW12,800 MW
29 Oct, 14:0013,849 MW13,036 MW
29 Oct, 15:0014,627 MW13,759 MW
29 Oct, 16:0015,982 MW15,180 MW
29 Oct, 17:0017,146 MW16,721 MW
29 Oct, 18:0017,723 MW17,494 MW
29 Oct, 19:0017,532 MW17,290 MW
29 Oct, 20:0017,050 MW16,759 MW
29 Oct, 21:0016,276 MW15,996 MW
29 Oct, 22:0015,329 MW15,082 MW
29 Oct, 23:0014,443 MW14,159 MW
30 Oct, 00:0013,762 MW13,506 MW
30 Oct, 01:0013,266 MW12,985 MW
30 Oct, 02:0012,946 MW12,639 MW
30 Oct, 03:0012,766 MW12,485 MW
30 Oct, 04:0012,858 MW12,622 MW
30 Oct, 05:0013,519 MW13,280 MW
30 Oct, 06:0014,813 MW14,647 MW
30 Oct, 07:0015,897 MW15,749 MW
30 Oct, 08:0016,136 MW15,832 MW
30 Oct, 09:0015,723 MW15,035 MW
30 Oct, 10:0015,282 MW14,359 MW
30 Oct, 11:0015,101 MW14,033 MW
30 Oct, 12:0014,930 MW13,854 MW
30 Oct, 13:0014,774 MW13,869 MW
30 Oct, 14:0014,695 MW13,965 MW
30 Oct, 15:0015,196 MW14,448 MW
30 Oct, 16:0015,946 MW15,437 MW
30 Oct, 17:0016,871 MW16,529 MW
30 Oct, 18:0017,163 MW17,001 MW
30 Oct, 19:0016,906 MW16,781 MW
30 Oct, 20:0016,494 MW16,292 MW
30 Oct, 21:0015,884 MW15,697 MW
30 Oct, 22:0015,161 MW14,965 MW
30 Oct, 23:0014,378 MW14,183 MW
31 Oct, 00:0013,822 MW13,464 MW
31 Oct, 01:0013,377 MW12,968 MW
31 Oct, 02:0013,069 MW12,674 MW
31 Oct, 03:0012,925 MW12,536 MW
31 Oct, 04:0012,935 MW12,557 MW
31 Oct, 05:0013,212 MW12,832 MW
31 Oct, 06:0013,801 MW13,456 MW
31 Oct, 07:0014,499 MW14,072 MW
31 Oct, 08:0014,542 MW13,892 MW
31 Oct, 09:0013,756 MW13,048 MW
31 Oct, 10:0013,006 MW12,315 MW
31 Oct, 11:0012,590 MW11,924 MW
31 Oct, 12:0012,354 MW11,679 MW
31 Oct, 13:0012,274 MW11,552 MW
31 Oct, 14:0012,308 MW11,606 MW
31 Oct, 15:0012,786 MW12,121 MW
31 Oct, 16:0014,047 MW13,310 MW
31 Oct, 17:0015,388 MW14,825 MW
31 Oct, 18:0015,952 MW15,680 MW
31 Oct, 19:0015,869 MW15,607 MW
31 Oct, 20:0015,700 MW15,423 MW
31 Oct, 21:0015,393 MW15,086 MW
31 Oct, 22:0014,852 MW14,576 MW
31 Oct, 23:0014,233 MW13,945 MW
1 Nov, 00:0013,781 MW13,387 MW
1 Nov, 01:0013,413 MW12,903 MW
1 Nov, 01:0013,158 MW12,903 MW
1 Nov, 02:0013,007 MW12,663 MW
1 Nov, 03:0012,968 MW12,542 MW
1 Nov, 04:0013,068 MW12,612 MW
1 Nov, 05:0013,231 MW12,910 MW
1 Nov, 06:0013,827 MW13,171 MW
1 Nov, 07:0013,808 MW12,804 MW
1 Nov, 08:0012,995 MW12,416 MW
1 Nov, 09:0012,158 MW11,790 MW
1 Nov, 10:0011,848 MW11,465 MW
1 Nov, 11:0011,784 MW11,394 MW
1 Nov, 12:0011,865 MW11,417 MW
1 Nov, 13:0012,148 MW11,650 MW
1 Nov, 14:0012,829 MW12,242 MW
1 Nov, 15:0014,328 MW13,399 MW
1 Nov, 16:0015,868 MW15,085 MW
1 Nov, 17:0016,841 MW16,352 MW
1 Nov, 18:0016,802 MW16,364 MW
1 Nov, 19:0016,491 MW15,949 MW
1 Nov, 20:0016,016 MW15,494 MW
1 Nov, 21:0015,367 MW14,959 MW
1 Nov, 22:0014,592 MW14,224 MW
1 Nov, 23:0013,879 MW13,502 MW
2 Nov, 00:0013,402 MW13,195 MW
2 Nov, 01:0013,058 MW12,826 MW
2 Nov, 02:0012,854 MW12,615 MW
2 Nov, 03:0012,819 MW12,559 MW
2 Nov, 04:0013,113 MW12,850 MW
2 Nov, 05:0013,971 MW13,712 MW
2 Nov, 06:0015,342 MW14,970 MW
2 Nov, 07:0015,863 MW15,377 MW
2 Nov, 08:0015,226 MW15,323 MW
2 Nov, 09:0014,383 MW14,747 MW
2 Nov, 10:0014,058 MW14,246 MW
2 Nov, 11:0013,931 MW14,059 MW
2 Nov, 12:0014,102 MW13,989 MW
2 Nov, 13:0014,533 MW14,168 MW
2 Nov, 14:0015,177 MW14,506 MW
2 Nov, 15:0016,099 MW15,386 MW
2 Nov, 16:0017,055 MW16,720 MW
2 Nov, 17:0017,869 MW17,702 MW
2 Nov, 18:0017,657 MW17,483 MW
2 Nov, 19:0017,211 MW16,985 MW
2 Nov, 20:0016,644 MW16,414 MW
2 Nov, 21:0015,853 MW15,741 MW
2 Nov, 22:0014,901 MW14,839 MW
2 Nov, 23:0013,988 MW13,973 MW
3 Nov, 00:0013,376 MW13,278 MW
3 Nov, 01:0012,927 MW12,835 MW
3 Nov, 02:0012,623 MW12,591 MW
3 Nov, 03:0012,542 MW12,508 MW
3 Nov, 04:0012,800 MW12,755 MW
3 Nov, 05:0013,607 MW13,537 MW
3 Nov, 06:0014,862 MW14,787 MW
3 Nov, 07:0015,586 MW15,300 MW
3 Nov, 08:0015,694 MW15,358 MW
3 Nov, 09:0015,545 MW14,974 MW
3 Nov, 10:0015,330 MW14,686 MW
3 Nov, 11:0015,223 MW14,670 MW
3 Nov, 12:0015,104 MW14,695 MW
3 Nov, 13:0015,287 MW14,980 MW
3 Nov, 14:0015,559 MW15,323 MW
3 Nov, 15:0016,275 MW15,990 MW
3 Nov, 16:0017,151 MW17,072 MW
3 Nov, 17:0017,913 MW17,926 MW
3 Nov, 18:0017,748 MW17,678 MW
3 Nov, 19:0017,284 MW17,137 MW
3 Nov, 20:0016,706 MW16,540 MW
3 Nov, 21:0015,916 MW15,837 MW
3 Nov, 22:0014,977 MW14,917 MW
3 Nov, 23:0014,057 MW14,036 MW
4 Nov, 00:0013,461 MW13,279 MW
4 Nov, 01:0012,967 MW12,813 MW
4 Nov, 02:0012,661 MW12,529 MW
4 Nov, 03:0012,552 MW12,416 MW
4 Nov, 04:0012,783 MW12,636 MW
4 Nov, 05:0013,559 MW13,399 MW
4 Nov, 06:0014,890 MW14,600 MW
4 Nov, 07:0015,343 MW14,642 MW
4 Nov, 08:0014,508 MW14,171 MW
4 Nov, 09:0013,942 MW13,556 MW
4 Nov, 10:0013,843 MW13,241 MW
4 Nov, 11:0013,939 MW13,333 MW
4 Nov, 12:0014,215 MW13,501 MW
4 Nov, 13:0014,674 MW13,970 MW
4 Nov, 14:0015,371 MW14,675 MW
4 Nov, 15:0016,497 MW15,763 MW
4 Nov, 16:0017,515 MW17,135 MW
4 Nov, 17:0018,184 MW18,041 MW
4 Nov, 18:0017,947 MW17,777 MW
4 Nov, 19:0017,507 MW17,206 MW
4 Nov, 20:0016,924 MW16,599 MW
4 Nov, 21:0016,172 MW15,873 MW
4 Nov, 22:0015,200 MW14,985 MW
4 Nov, 23:0014,293 MW14,123 MW
5 Nov, 00:0013,679 MW13,270 MW
5 Nov, 01:0013,236 MW12,818 MW
5 Nov, 02:0012,958 MW12,553 MW
5 Nov, 03:0012,838 MW12,453 MW
5 Nov, 04:0013,007 MW12,681 MW
5 Nov, 05:0013,727 MW13,465 MW
5 Nov, 06:0015,095 MW14,849 MW
5 Nov, 07:0016,104 MW15,802 MW
5 Nov, 08:0016,451 MW16,160 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 2026-11-05. 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 2026-11-05. Data from U.S. Energy Information Administration.},
  url = {https://worldpowermonitor.com/forecast-accuracy/nyiso/}
}

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