Statistics
Page built 2026-10-28
Data as of 2026-10-28
Search
Built 2026-10-28 (28 October 2026)

AZPS Demand Forecast Accuracy: Error, Bias and Worst Miss, 28 September to 28 October 2026

The day-ahead demand forecast for AZPS was off by 13.2% on average (mean absolute percentage error) over 715 hours from 28 September to 28 October 2026, and 15% of hours landed within 5% of the reading. Its bias was -8.7%: it ran low on average, an under forecast. The largest miss was 3,894 MW (164.9%) too high at 6 Oct 2026, 18:00 MST (UTC-07:00). Dates and times are local (America/Phoenix).

Key Facts

  • The day-ahead demand forecast for AZPS was off by 13.2% on average (mean absolute percentage error) over 715 hours from 28 September to 28 October 2026, and 15% of hours landed within 5% of the reading. Its bias was -8.7%: it ran low on average, an under forecast. The largest miss was 3,894 MW (164.9%) too high at 6 Oct 2026, 18:00 MST (UTC-07:00).
  • Across 53 US grids ranked by average error over their own latest 30 day windows, AZPS came 46 (1 is the smallest error).
  • On average the forecast differed from reported demand by 622 MW, against average demand of 4,764 MW.
  • The forecast was above reported demand in 21% of compared hours.

Forecast Error at a Glance

715 hours from 28 September to 28 October 2026
Average error13.2%
Bias-8.7%
Hours within 5%15%
Worst miss3,894 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (-467 MW per hour on average): the forecast ran low on average, an under forecast. The worst miss was 3,894 MW (164.9%) too high at 6 Oct 2026, 18:00 MST (UTC-07:00): forecast 6,255 MW, reported 2,361 MW.

Source: U.S. Energy Information Administration (EIA). (US Government work, public domain) Data as of 2026-10-28. 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 28 Oct 2026, 04:00 MST (UTC-07:00)
AZPS day-ahead demand forecast and reported demand by hour Hourly reported demand and the day-ahead forecast for AZPS over the last 7 days of the window, to 28 Oct 2026, 04:00 MST (UTC-07:00). Gaps are hours with a missing, zero or implausible report. 0 1,500 3,000 4,500 6,000 21 Oct, 05:0022 Oct, 05:0023 Oct, 05:0024 Oct, 05:0025 Oct, 05:0026 Oct, 05:0027 Oct, 05:00
Hourly reported demand and the day-ahead forecast for AZPS over the last 7 days of the window, to 28 Oct 2026, 04:00 MST (UTC-07:00). Gaps are hours with a missing, zero or implausible report.
Data to 2026-10-28
Show the data table (168 rows)
Local hourReported demandDay-ahead forecast
21 Oct, 05:004,694 MW4,271 MW
21 Oct, 06:004,841 MW4,278 MW
21 Oct, 07:004,811 MW4,240 MW
21 Oct, 08:004,411 MW4,171 MW
21 Oct, 09:004,050 MW4,147 MW
21 Oct, 10:004,117 MW4,204 MW
21 Oct, 11:004,192 MW4,309 MW
21 Oct, 12:004,230 MW4,420 MW
21 Oct, 13:004,681 MW4,468 MW
21 Oct, 14:004,968 MW4,607 MW
21 Oct, 15:005,160 MW4,725 MW
21 Oct, 16:005,194 MW4,688 MW
21 Oct, 17:005,461 MW4,722 MW
21 Oct, 18:005,897 MW4,741 MW
21 Oct, 19:005,820 MW4,748 MW
21 Oct, 20:005,741 MW4,694 MW
21 Oct, 21:005,538 MW4,459 MW
21 Oct, 22:005,279 MW4,178 MW
21 Oct, 23:004,953 MW4,079 MW
22 Oct, 00:004,950 MW4,148 MW
22 Oct, 01:004,775 MW4,149 MW
22 Oct, 02:004,528 MW4,108 MW
22 Oct, 03:004,503 MW4,101 MW
22 Oct, 04:004,534 MW4,223 MW
22 Oct, 05:004,715 MW4,322 MW
22 Oct, 06:004,909 MW4,336 MW
22 Oct, 07:004,818 MW4,241 MW
22 Oct, 08:004,277 MW4,118 MW
22 Oct, 09:003,924 MW4,014 MW
22 Oct, 10:004,171 MW4,050 MW
22 Oct, 11:004,091 MW4,121 MW
22 Oct, 12:004,190 MW4,248 MW
22 Oct, 13:004,581 MW4,253 MW
22 Oct, 14:004,646 MW4,403 MW
22 Oct, 15:004,694 MW4,453 MW
22 Oct, 16:005,040 MW4,560 MW
22 Oct, 17:005,590 MW4,643 MW
22 Oct, 18:005,506 MW4,700 MW
22 Oct, 19:005,581 MW4,548 MW
22 Oct, 20:005,389 MW4,356 MW
22 Oct, 21:005,120 MW4,135 MW
22 Oct, 22:004,879 MW3,827 MW
22 Oct, 23:004,448 MW3,636 MW
23 Oct, 00:004,285 MW3,484 MW
23 Oct, 01:004,129 MW3,631 MW
23 Oct, 02:004,171 MW3,578 MW
23 Oct, 03:004,192 MW3,648 MW
23 Oct, 04:004,156 MW3,771 MW
23 Oct, 05:004,306 MW3,880 MW
23 Oct, 06:004,411 MW3,827 MW
23 Oct, 07:004,021 MW3,682 MW
23 Oct, 08:004,448 MW3,497 MW
23 Oct, 09:005,193 MW3,385 MW
23 Oct, 10:005,591 MW3,366 MW
23 Oct, 11:005,643 MW3,492 MW
23 Oct, 12:005,498 MW3,559 MW
23 Oct, 13:005,197 MW3,788 MW
23 Oct, 14:005,135 MW4,026 MW
23 Oct, 15:004,953 MW4,301 MW
23 Oct, 16:004,676 MW4,435 MW
23 Oct, 17:005,130 MW4,455 MW
23 Oct, 18:005,020 MW4,345 MW
23 Oct, 19:005,184 MW4,102 MW
23 Oct, 20:004,835 MW3,903 MW
23 Oct, 21:00n/a3,732 MW
23 Oct, 22:004,520 MW3,556 MW
23 Oct, 23:004,250 MW3,419 MW
24 Oct, 00:004,205 MW3,273 MW
24 Oct, 01:004,258 MW3,282 MW
24 Oct, 02:004,153 MW3,280 MW
24 Oct, 03:004,127 MW3,222 MW
24 Oct, 04:004,086 MW3,321 MW
24 Oct, 05:004,112 MW3,442 MW
24 Oct, 06:004,156 MW3,477 MW
24 Oct, 07:003,932 MW3,399 MW
24 Oct, 08:003,163 MW3,174 MW
24 Oct, 09:002,889 MW3,115 MW
24 Oct, 10:002,813 MW3,114 MW
24 Oct, 11:002,875 MW3,079 MW
24 Oct, 12:003,114 MW3,269 MW
24 Oct, 13:003,293 MW3,454 MW
24 Oct, 14:003,286 MW3,702 MW
24 Oct, 15:003,348 MW3,938 MW
24 Oct, 16:003,895 MW4,139 MW
24 Oct, 17:004,986 MW4,240 MW
24 Oct, 18:005,052 MW4,099 MW
24 Oct, 19:004,867 MW3,997 MW
24 Oct, 20:004,708 MW3,926 MW
24 Oct, 21:004,711 MW3,743 MW
24 Oct, 22:004,250 MW3,582 MW
24 Oct, 23:004,073 MW3,254 MW
25 Oct, 00:004,061 MW3,277 MW
25 Oct, 01:003,947 MW3,419 MW
25 Oct, 02:003,960 MW3,368 MW
25 Oct, 03:004,014 MW3,413 MW
25 Oct, 04:003,947 MW3,443 MW
25 Oct, 05:003,928 MW3,508 MW
25 Oct, 06:004,071 MW3,496 MW
25 Oct, 07:003,802 MW3,370 MW
25 Oct, 08:002,955 MW3,123 MW
25 Oct, 09:002,422 MW2,979 MW
25 Oct, 10:002,263 MW2,949 MW
25 Oct, 11:002,522 MW3,025 MW
25 Oct, 12:002,614 MW3,226 MW
25 Oct, 13:002,688 MW3,430 MW
25 Oct, 14:003,278 MW3,731 MW
25 Oct, 15:003,525 MW4,120 MW
25 Oct, 16:004,128 MW4,296 MW
25 Oct, 17:004,869 MW4,516 MW
25 Oct, 18:005,126 MW4,282 MW
25 Oct, 19:004,975 MW4,073 MW
25 Oct, 20:004,788 MW3,894 MW
25 Oct, 21:004,739 MW3,606 MW
25 Oct, 22:004,346 MW3,430 MW
25 Oct, 23:004,152 MW3,323 MW
26 Oct, 00:004,016 MW3,479 MW
26 Oct, 01:003,970 MW3,396 MW
26 Oct, 02:003,910 MW3,409 MW
26 Oct, 03:004,000 MW3,487 MW
26 Oct, 04:003,989 MW3,626 MW
26 Oct, 05:004,116 MW3,828 MW
26 Oct, 06:004,236 MW3,746 MW
26 Oct, 07:003,998 MW3,549 MW
26 Oct, 08:003,174 MW3,316 MW
26 Oct, 09:002,587 MW3,240 MW
26 Oct, 10:002,468 MW3,187 MW
26 Oct, 11:002,681 MW3,257 MW
26 Oct, 12:003,036 MW3,406 MW
26 Oct, 13:003,556 MW3,730 MW
26 Oct, 14:003,689 MW4,078 MW
26 Oct, 15:003,979 MW4,320 MW
26 Oct, 16:004,421 MW4,550 MW
26 Oct, 17:004,823 MW4,585 MW
26 Oct, 18:004,935 MW4,507 MW
26 Oct, 19:005,016 MW4,364 MW
26 Oct, 20:004,747 MW4,104 MW
26 Oct, 21:004,485 MW3,897 MW
26 Oct, 22:004,145 MW3,691 MW
26 Oct, 23:003,999 MW3,540 MW
27 Oct, 00:004,008 MW3,593 MW
27 Oct, 01:003,955 MW3,516 MW
27 Oct, 02:003,937 MW3,504 MW
27 Oct, 03:003,944 MW3,555 MW
27 Oct, 04:003,979 MW3,702 MW
27 Oct, 05:004,147 MW3,886 MW
27 Oct, 06:004,370 MW3,802 MW
27 Oct, 07:004,292 MW3,608 MW
27 Oct, 08:003,405 MW3,436 MW
27 Oct, 09:002,985 MW3,281 MW
27 Oct, 10:002,957 MW3,280 MW
27 Oct, 11:003,008 MW3,368 MW
27 Oct, 12:002,902 MW3,570 MW
27 Oct, 13:003,284 MW3,916 MW
27 Oct, 14:003,913 MW4,235 MW
27 Oct, 15:004,146 MW4,459 MW
27 Oct, 16:004,296 MW4,664 MW
27 Oct, 17:005,025 MW4,707 MW
27 Oct, 18:004,999 MW4,582 MW
27 Oct, 19:004,971 MW4,408 MW
27 Oct, 20:004,979 MW4,142 MW
27 Oct, 21:004,739 MW3,906 MW
27 Oct, 22:004,498 MW3,710 MW
27 Oct, 23:004,302 MW3,544 MW
28 Oct, 00:004,239 MW3,659 MW
28 Oct, 01:004,115 MW3,317 MW
28 Oct, 02:004,145 MW3,306 MW
28 Oct, 03:004,133 MW3,434 MW
28 Oct, 04:003,592 MW3,592 MW

Assumptions

  • Only hours with both a forecast and a positive demand reading count (715 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). AZPS Demand Forecast Accuracy: Error, Bias and Worst Miss. https://worldpowermonitor.com/forecast-accuracy/azps/

Plain text

World Power Monitor. AZPS Demand Forecast Accuracy: Error, Bias and Worst Miss. Data as of 2026-10-28. Data from U.S. Energy Information Administration. https://worldpowermonitor.com/forecast-accuracy/azps/

BibTeX 
@misc{wpm_forecast_accuracy_azps_2026,
  title = {{AZPS Demand Forecast Accuracy: Error, Bias and Worst Miss}},
  author = {{World Power Monitor}},
  year = {2026},
  note = {Data as of 2026-10-28. Data from U.S. Energy Information Administration.},
  url = {https://worldpowermonitor.com/forecast-accuracy/azps/}
}

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

The Copy buttons add today's date as the access date.