Italy Calabria Demand Forecast Accuracy: Error, Bias and Worst Miss, 23 August to 20 September 2026
The day-ahead demand forecast for Italy Calabria was off by 8.6% on average (mean absolute percentage error) over 686 hours from 23 August to 20 September 2026, and 33% of hours landed within 5% of the reading. Its bias was +0.9%: it ran high on average, an over forecast. The largest miss was 271 MW (21.5%) too low at 29 Aug 2026, 14:00 CEST (UTC+02:00). Dates and times are local (Europe/Rome).
Key Facts
- The day-ahead demand forecast for Italy Calabria was off by 8.6% on average (mean absolute percentage error) over 686 hours from 23 August to 20 September 2026, and 33% of hours landed within 5% of the reading. Its bias was +0.9%: it ran high on average, an over forecast. The largest miss was 271 MW (21.5%) too low at 29 Aug 2026, 14:00 CEST (UTC+02:00).
- Across 47 European bidding zones ranked by average error over their own latest 30 day windows, Italy Calabria came 39 (1 is the smallest error).
- On average the forecast differed from reported demand by 69 MW, against average demand of 816 MW.
- The forecast was above reported demand in 51% of compared hours.
Forecast Error at a Glance
686 hours from 23 August to 20 September 2026Average error8.6%
Bias+0.9%
Hours within 5%33%
Worst miss271 MW
Average error is the mean absolute percentage gap between the forecast and reported demand. Bias is the signed mean (-1 MW per hour on average): the forecast ran high on average, an over forecast. The worst miss was 271 MW (21.5%) too low at 29 Aug 2026, 14:00 CEST (UTC+02:00): forecast 993 MW, reported 1,264 MW.
Source: ENTSO-E Transparency Platform (transparency.entsoe.eu), CC BY 4.0. Aggregated and converted by World Power Monitor; ENTSO-E does not endorse this site. (ENTSO-E Terms of Use plus CC BY 4.0 for listed data items) Data as of 2026-09-20. 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 20 Sept 2026, 13:00 CEST (UTC+02:00)Data to 2026-09-20
| Local hour | Reported demand | Day-ahead forecast |
|---|---|---|
| 13 Sept, 14:00 | 553 MW | 668 MW |
| 13 Sept, 15:00 | 560 MW | 670 MW |
| 13 Sept, 16:00 | 550 MW | 690 MW |
| 13 Sept, 17:00 | 582 MW | 733 MW |
| 13 Sept, 18:00 | 659 MW | 763 MW |
| 13 Sept, 19:00 | 754 MW | 798 MW |
| 13 Sept, 20:00 | 730 MW | 843 MW |
| 13 Sept, 21:00 | 710 MW | 810 MW |
| 13 Sept, 22:00 | 663 MW | 730 MW |
| 13 Sept, 23:00 | 574 MW | 650 MW |
| 14 Sept, 00:00 | 525 MW | 588 MW |
| 14 Sept, 01:00 | 477 MW | 545 MW |
| 14 Sept, 02:00 | 465 MW | 478 MW |
| 14 Sept, 03:00 | 464 MW | 473 MW |
| 14 Sept, 04:00 | 463 MW | 475 MW |
| 14 Sept, 05:00 | 496 MW | 470 MW |
| 14 Sept, 06:00 | 537 MW | 560 MW |
| 14 Sept, 07:00 | 607 MW | 658 MW |
| 14 Sept, 08:00 | 723 MW | 698 MW |
| 14 Sept, 09:00 | 694 MW | 675 MW |
| 14 Sept, 10:00 | 651 MW | 668 MW |
| 14 Sept, 11:00 | 624 MW | 650 MW |
| 14 Sept, 12:00 | 653 MW | 640 MW |
| 14 Sept, 13:00 | 632 MW | 645 MW |
| 14 Sept, 14:00 | 622 MW | 640 MW |
| 14 Sept, 15:00 | 659 MW | 690 MW |
| 14 Sept, 16:00 | 671 MW | 708 MW |
| 14 Sept, 17:00 | 722 MW | 758 MW |
| 14 Sept, 18:00 | 822 MW | 830 MW |
| 14 Sept, 19:00 | 894 MW | 913 MW |
| 14 Sept, 20:00 | 879 MW | 915 MW |
| 14 Sept, 21:00 | 843 MW | 843 MW |
| 14 Sept, 22:00 | 725 MW | 765 MW |
| 14 Sept, 23:00 | 663 MW | 690 MW |
| 15 Sept, 00:00 | 588 MW | 665 MW |
| 15 Sept, 01:00 | 536 MW | 598 MW |
| 15 Sept, 02:00 | 509 MW | 570 MW |
| 15 Sept, 03:00 | 492 MW | 563 MW |
| 15 Sept, 04:00 | 498 MW | 565 MW |
| 15 Sept, 05:00 | 528 MW | 618 MW |
| 15 Sept, 06:00 | 600 MW | 675 MW |
| 15 Sept, 07:00 | 708 MW | 725 MW |
| 15 Sept, 08:00 | 763 MW | 780 MW |
| 15 Sept, 09:00 | 732 MW | 795 MW |
| 15 Sept, 10:00 | 711 MW | 798 MW |
| 15 Sept, 11:00 | 696 MW | 768 MW |
| 15 Sept, 12:00 | 703 MW | 753 MW |
| 15 Sept, 13:00 | 696 MW | 773 MW |
| 15 Sept, 14:00 | 692 MW | 773 MW |
| 15 Sept, 15:00 | 689 MW | 778 MW |
| 15 Sept, 16:00 | 709 MW | 805 MW |
| 15 Sept, 17:00 | 681 MW | 813 MW |
| 15 Sept, 18:00 | 778 MW | 878 MW |
| 15 Sept, 19:00 | 884 MW | 973 MW |
| 15 Sept, 20:00 | 864 MW | 960 MW |
| 15 Sept, 21:00 | 799 MW | 850 MW |
| 15 Sept, 22:00 | 690 MW | 800 MW |
| 15 Sept, 23:00 | 627 MW | 700 MW |
| 16 Sept, 00:00 | 590 MW | 638 MW |
| 16 Sept, 01:00 | 558 MW | 590 MW |
| 16 Sept, 02:00 | 524 MW | 563 MW |
| 16 Sept, 03:00 | 505 MW | 545 MW |
| 16 Sept, 04:00 | 516 MW | 548 MW |
| 16 Sept, 05:00 | 550 MW | 585 MW |
| 16 Sept, 06:00 | 587 MW | 663 MW |
| 16 Sept, 07:00 | 641 MW | 715 MW |
| 16 Sept, 08:00 | 669 MW | 768 MW |
| 16 Sept, 09:00 | 671 MW | 773 MW |
| 16 Sept, 10:00 | 646 MW | 763 MW |
| 16 Sept, 11:00 | 618 MW | 738 MW |
| 16 Sept, 12:00 | 555 MW | 720 MW |
| 16 Sept, 13:00 | 563 MW | 755 MW |
| 16 Sept, 14:00 | 606 MW | 795 MW |
| 16 Sept, 15:00 | 631 MW | 793 MW |
| 16 Sept, 16:00 | 642 MW | 798 MW |
| 16 Sept, 17:00 | 721 MW | 823 MW |
| 16 Sept, 18:00 | 774 MW | 875 MW |
| 16 Sept, 19:00 | 880 MW | 980 MW |
| 16 Sept, 20:00 | 892 MW | 970 MW |
| 16 Sept, 21:00 | 807 MW | 875 MW |
| 16 Sept, 22:00 | 731 MW | 810 MW |
| 16 Sept, 23:00 | 648 MW | 715 MW |
| 17 Sept, 00:00 | 588 MW | 585 MW |
| 17 Sept, 01:00 | 544 MW | 523 MW |
| 17 Sept, 02:00 | 515 MW | 505 MW |
| 17 Sept, 03:00 | 505 MW | 500 MW |
| 17 Sept, 04:00 | 503 MW | 500 MW |
| 17 Sept, 05:00 | 529 MW | 525 MW |
| 17 Sept, 06:00 | 574 MW | 578 MW |
| 17 Sept, 07:00 | 643 MW | 648 MW |
| 17 Sept, 08:00 | 678 MW | 743 MW |
| 17 Sept, 09:00 | 697 MW | 720 MW |
| 17 Sept, 10:00 | 683 MW | 663 MW |
| 17 Sept, 11:00 | 681 MW | 640 MW |
| 17 Sept, 12:00 | 669 MW | 650 MW |
| 17 Sept, 13:00 | 650 MW | 635 MW |
| 17 Sept, 14:00 | 637 MW | 633 MW |
| 17 Sept, 15:00 | 668 MW | 658 MW |
| 17 Sept, 16:00 | 725 MW | 685 MW |
| 17 Sept, 17:00 | 756 MW | 738 MW |
| 17 Sept, 18:00 | 836 MW | 845 MW |
| 17 Sept, 19:00 | 907 MW | 903 MW |
| 17 Sept, 20:00 | 874 MW | 883 MW |
| 17 Sept, 21:00 | 822 MW | 840 MW |
| 17 Sept, 22:00 | 786 MW | 728 MW |
| 17 Sept, 23:00 | 616 MW | 655 MW |
| 18 Sept, 00:00 | 591 MW | 598 MW |
| 18 Sept, 01:00 | 570 MW | 570 MW |
| 18 Sept, 02:00 | 543 MW | 540 MW |
| 18 Sept, 03:00 | 529 MW | 533 MW |
| 18 Sept, 04:00 | 534 MW | 543 MW |
| 18 Sept, 05:00 | 552 MW | 570 MW |
| 18 Sept, 06:00 | 588 MW | 610 MW |
| 18 Sept, 07:00 | 644 MW | 678 MW |
| 18 Sept, 08:00 | 700 MW | 713 MW |
| 18 Sept, 09:00 | 709 MW | 708 MW |
| 18 Sept, 10:00 | 726 MW | 683 MW |
| 18 Sept, 11:00 | 709 MW | 670 MW |
| 18 Sept, 12:00 | 696 MW | 645 MW |
| 18 Sept, 13:00 | 669 MW | 655 MW |
| 18 Sept, 14:00 | 658 MW | 698 MW |
| 18 Sept, 15:00 | 696 MW | 715 MW |
| 18 Sept, 16:00 | 665 MW | 735 MW |
| 18 Sept, 17:00 | 712 MW | 755 MW |
| 18 Sept, 18:00 | 765 MW | 813 MW |
| 18 Sept, 19:00 | 874 MW | 910 MW |
| 18 Sept, 20:00 | 843 MW | 890 MW |
| 18 Sept, 21:00 | 775 MW | 823 MW |
| 18 Sept, 22:00 | 698 MW | 738 MW |
| 18 Sept, 23:00 | 647 MW | 675 MW |
| 19 Sept, 00:00 | 629 MW | 605 MW |
| 19 Sept, 01:00 | 585 MW | 560 MW |
| 19 Sept, 02:00 | 551 MW | 528 MW |
| 19 Sept, 03:00 | 563 MW | 515 MW |
| 19 Sept, 04:00 | 548 MW | 520 MW |
| 19 Sept, 05:00 | 580 MW | 530 MW |
| 19 Sept, 06:00 | 598 MW | 550 MW |
| 19 Sept, 07:00 | 610 MW | 598 MW |
| 19 Sept, 08:00 | 638 MW | 648 MW |
| 19 Sept, 09:00 | 679 MW | 645 MW |
| 19 Sept, 10:00 | 670 MW | 633 MW |
| 19 Sept, 11:00 | 669 MW | 628 MW |
| 19 Sept, 12:00 | 670 MW | 620 MW |
| 19 Sept, 13:00 | 624 MW | 588 MW |
| 19 Sept, 14:00 | 613 MW | 570 MW |
| 19 Sept, 15:00 | 610 MW | 605 MW |
| 19 Sept, 16:00 | 622 MW | 630 MW |
| 19 Sept, 17:00 | 703 MW | 668 MW |
| 19 Sept, 18:00 | 763 MW | 708 MW |
| 19 Sept, 19:00 | 837 MW | 838 MW |
| 19 Sept, 20:00 | 804 MW | 835 MW |
| 19 Sept, 21:00 | 717 MW | 735 MW |
| 19 Sept, 22:00 | 660 MW | 683 MW |
| 19 Sept, 23:00 | 606 MW | 605 MW |
| 20 Sept, 00:00 | 587 MW | 555 MW |
| 20 Sept, 01:00 | 554 MW | 513 MW |
| 20 Sept, 02:00 | 528 MW | 488 MW |
| 20 Sept, 03:00 | 514 MW | 470 MW |
| 20 Sept, 04:00 | 511 MW | 470 MW |
| 20 Sept, 05:00 | 518 MW | 473 MW |
| 20 Sept, 06:00 | 521 MW | 478 MW |
| 20 Sept, 07:00 | 533 MW | 493 MW |
| 20 Sept, 08:00 | 579 MW | 530 MW |
| 20 Sept, 09:00 | 582 MW | 548 MW |
| 20 Sept, 10:00 | 602 MW | 543 MW |
| 20 Sept, 11:00 | 620 MW | 533 MW |
| 20 Sept, 12:00 | 646 MW | 543 MW |
| 20 Sept, 13:00 | 604 MW | 523 MW |
Assumptions
- Only hours with both a forecast and a positive demand reading count (686 of 686 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.
- European figures are for the ENTSO-E bidding zone named on this page. US and European grids are ranked separately.