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

The day-ahead demand forecast for IID was off by 3.3% on average (mean absolute percentage error) over 695 hours from 13 October to 12 November 2026, and 79% of hours landed within 5% of the reading. Its bias was +0.6%: it ran high on average, an over forecast. The largest miss was 69 MW (17.4%) too high at 17 Oct 2026, 16:00 PDT (UTC-07:00). Dates and times are local (America/Los_Angeles).

Key Facts

The day-ahead demand forecast for IID was off by 3.3% on average (mean absolute percentage error) over 695 hours from 13 October to 12 November 2026, and 79% of hours landed within 5% of the reading. Its bias was +0.6%: it ran high on average, an over forecast. The largest miss was 69 MW (17.4%) too high at 17 Oct 2026, 16:00 PDT (UTC-07:00).
Across 53 US grids ranked by average error over their own latest 30 day windows, IID came 23 (1 is the smallest error).
On average the forecast differed from reported demand by 12 MW, against average demand of 350 MW.
The forecast was above reported demand in 55% of compared hours.

Forecast Error at a Glance

695 hours from 13 October to 12 November 2026

Average error3.3%

Bias+0.6%

Hours within 5%79%

Worst miss69 MW

Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (+2 MW per hour on average): the forecast ran high on average, an over forecast. The worst miss was 69 MW (17.4%) too high at 17 Oct 2026, 16:00 PDT (UTC-07:00): forecast 466 MW, reported 397 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, 04:00 PST (UTC-08:00)

Hourly reported demand and the day-ahead forecast for IID over the last 7 days of the window, to 12 Nov 2026, 04:00 PST (UTC-08:00). 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, 05:00	276 MW	261 MW
5 Nov, 06:00	291 MW	280 MW
5 Nov, 07:00	301 MW	298 MW
5 Nov, 08:00	302 MW	307 MW
5 Nov, 09:00	312 MW	311 MW
5 Nov, 10:00	318 MW	323 MW
5 Nov, 11:00	332 MW	332 MW
5 Nov, 12:00	349 MW	342 MW
5 Nov, 13:00	384 MW	369 MW
5 Nov, 14:00	410 MW	399 MW
5 Nov, 15:00	423 MW	420 MW
5 Nov, 16:00	431 MW	433 MW
5 Nov, 17:00	429 MW	428 MW
5 Nov, 18:00	398 MW	408 MW
5 Nov, 19:00	377 MW	392 MW
5 Nov, 20:00	361 MW	372 MW
5 Nov, 21:00	335 MW	360 MW
5 Nov, 22:00	306 MW	326 MW
5 Nov, 23:00	281 MW	303 MW
6 Nov, 00:00	275 MW	275 MW
6 Nov, 01:00	250 MW	262 MW
6 Nov, 02:00	253 MW	253 MW
6 Nov, 03:00	247 MW	250 MW
6 Nov, 04:00	257 MW	257 MW
6 Nov, 05:00	267 MW	273 MW
6 Nov, 06:00	289 MW	292 MW
6 Nov, 07:00	293 MW	302 MW
6 Nov, 08:00	309 MW	312 MW
6 Nov, 09:00	312 MW	319 MW
6 Nov, 10:00	316 MW	332 MW
6 Nov, 11:00	337 MW	347 MW
6 Nov, 12:00	358 MW	365 MW
6 Nov, 13:00	391 MW	395 MW
6 Nov, 14:00	409 MW	418 MW
6 Nov, 15:00	431 MW	433 MW
6 Nov, 16:00	429 MW	440 MW
6 Nov, 17:00	416 MW	438 MW
6 Nov, 18:00	395 MW	416 MW
6 Nov, 19:00	375 MW	392 MW
6 Nov, 20:00	365 MW	373 MW
6 Nov, 21:00	345 MW	352 MW
6 Nov, 22:00	322 MW	327 MW
6 Nov, 23:00	300 MW	301 MW
7 Nov, 00:00	282 MW	287 MW
7 Nov, 01:00	266 MW	267 MW
7 Nov, 02:00	265 MW	260 MW
7 Nov, 03:00	260 MW	255 MW
7 Nov, 04:00	257 MW	254 MW
7 Nov, 05:00	268 MW	262 MW
7 Nov, 06:00	273 MW	268 MW
7 Nov, 07:00	277 MW	277 MW
7 Nov, 08:00	298 MW	287 MW
7 Nov, 09:00	311 MW	306 MW
7 Nov, 10:00	327 MW	321 MW
7 Nov, 11:00	356 MW	340 MW
7 Nov, 12:00	384 MW	362 MW
7 Nov, 13:00	407 MW	395 MW
7 Nov, 14:00	443 MW	422 MW
7 Nov, 15:00	465 MW	445 MW
7 Nov, 16:00	448 MW	450 MW
7 Nov, 17:00	436 MW	443 MW
7 Nov, 18:00	405 MW	417 MW
7 Nov, 19:00	375 MW	386 MW
7 Nov, 20:00	359 MW	365 MW
7 Nov, 21:00	338 MW	345 MW
7 Nov, 22:00	315 MW	321 MW
7 Nov, 23:00	287 MW	303 MW
8 Nov, 00:00	273 MW	280 MW
8 Nov, 01:00	260 MW	262 MW
8 Nov, 02:00	252 MW	256 MW
8 Nov, 03:00	248 MW	249 MW
8 Nov, 04:00	244 MW	247 MW
8 Nov, 05:00	249 MW	252 MW
8 Nov, 06:00	256 MW	252 MW
8 Nov, 07:00	255 MW	258 MW
8 Nov, 08:00	265 MW	269 MW
8 Nov, 09:00	281 MW	289 MW
8 Nov, 10:00	300 MW	309 MW
8 Nov, 11:00	328 MW	330 MW
8 Nov, 12:00	365 MW	357 MW
8 Nov, 13:00	401 MW	391 MW
8 Nov, 14:00	443 MW	419 MW
8 Nov, 15:00	459 MW	444 MW
8 Nov, 16:00	457 MW	451 MW
8 Nov, 17:00	431 MW	442 MW
8 Nov, 18:00	408 MW	420 MW
8 Nov, 19:00	380 MW	391 MW
8 Nov, 20:00	358 MW	372 MW
8 Nov, 21:00	337 MW	347 MW
8 Nov, 22:00	305 MW	318 MW
8 Nov, 23:00	285 MW	298 MW
9 Nov, 00:00	263 MW	276 MW
9 Nov, 01:00	251 MW	259 MW
9 Nov, 02:00	244 MW	253 MW
9 Nov, 03:00	244 MW	251 MW
9 Nov, 04:00	252 MW	256 MW
9 Nov, 05:00	266 MW	274 MW
9 Nov, 06:00	294 MW	295 MW
9 Nov, 07:00	291 MW	311 MW
9 Nov, 08:00	307 MW	321 MW
9 Nov, 09:00	320 MW	336 MW
9 Nov, 10:00	338 MW	353 MW
9 Nov, 11:00	360 MW	376 MW
9 Nov, 12:00	393 MW	404 MW
9 Nov, 13:00	427 MW	437 MW
9 Nov, 14:00	460 MW	464 MW
9 Nov, 15:00	482 MW	487 MW
9 Nov, 16:00	469 MW	489 MW
9 Nov, 17:00	456 MW	480 MW
9 Nov, 18:00	426 MW	453 MW
9 Nov, 19:00	402 MW	421 MW
9 Nov, 20:00	383 MW	397 MW
9 Nov, 21:00	357 MW	368 MW
9 Nov, 22:00	326 MW	335 MW
9 Nov, 23:00	297 MW	313 MW
10 Nov, 00:00	278 MW	279 MW
10 Nov, 01:00	266 MW	265 MW
10 Nov, 02:00	251 MW	257 MW
10 Nov, 03:00	246 MW	255 MW
10 Nov, 04:00	259 MW	263 MW
10 Nov, 05:00	277 MW	279 MW
10 Nov, 06:00	292 MW	301 MW
10 Nov, 07:00	314 MW	306 MW
10 Nov, 08:00	302 MW	317 MW
10 Nov, 09:00	316 MW	327 MW
10 Nov, 10:00	337 MW	343 MW
10 Nov, 11:00	360 MW	369 MW
10 Nov, 12:00	399 MW	400 MW
10 Nov, 13:00	443 MW	433 MW
10 Nov, 14:00	468 MW	466 MW
10 Nov, 15:00	495 MW	486 MW
10 Nov, 16:00	481 MW	488 MW
10 Nov, 17:00	466 MW	472 MW
10 Nov, 18:00	427 MW	445 MW
10 Nov, 19:00	407 MW	413 MW
10 Nov, 20:00	375 MW	386 MW
10 Nov, 21:00	352 MW	358 MW
10 Nov, 22:00	327 MW	330 MW
10 Nov, 23:00	296 MW	304 MW
11 Nov, 00:00	279 MW	283 MW
11 Nov, 01:00	258 MW	268 MW
11 Nov, 02:00	257 MW	259 MW
11 Nov, 03:00	251 MW	250 MW
11 Nov, 04:00	257 MW	251 MW
11 Nov, 05:00	272 MW	257 MW
11 Nov, 06:00	281 MW	262 MW
11 Nov, 07:00	295 MW	266 MW
11 Nov, 08:00	304 MW	282 MW
11 Nov, 09:00	318 MW	296 MW
11 Nov, 10:00	325 MW	317 MW
11 Nov, 11:00	362 MW	338 MW
11 Nov, 12:00	391 MW	367 MW
11 Nov, 13:00	432 MW	402 MW
11 Nov, 14:00	457 MW	434 MW
11 Nov, 15:00	472 MW	452 MW
11 Nov, 16:00	466 MW	451 MW
11 Nov, 17:00	455 MW	435 MW
11 Nov, 18:00	418 MW	412 MW
11 Nov, 19:00	394 MW	381 MW
11 Nov, 20:00	367 MW	359 MW
11 Nov, 21:00	349 MW	335 MW
11 Nov, 22:00	315 MW	311 MW
11 Nov, 23:00	293 MW	288 MW
12 Nov, 00:00	269 MW	269 MW
12 Nov, 01:00	256 MW	256 MW
12 Nov, 02:00	249 MW	249 MW
12 Nov, 03:00	244 MW	244 MW
12 Nov, 04:00	251 MW	251 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). IID Demand Forecast Accuracy: Error, Bias and Worst Miss. https://worldpowermonitor.com/forecast-accuracy/iid/

Plain text

World Power Monitor. IID 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/iid/

BibTeX

@misc{wpm_forecast_accuracy_iid_2026,
  title = {{IID 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/iid/}
}

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

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IID 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

Related