IESO Demand by Region (hourly)

Hourly Ontario demand and demand in each of IESO's ten demand regions (Toronto, Ottawa, Essa and the rest), since 2003.

Load data IESO market

Query with the agent

Native record

hour

daily, for the previous day publication cadence

Evidence

Observed market data

Published observations from the named source

Time basis

Point-in-time records

UTC · event_time

Overview

Hourly Ontario demand and demand in each of IESO's ten demand regions (Toronto, Ottawa, Essa and the rest), since 2003.

Query contract

Preserve one canonical row per (event_time) before aggregating.

Analysis rules

Rows repeat across polls: dedupe with argMax(value, ingested_at) per key.

Interpretation

event_time marks the END of the interval or hour. IESO delivers on EST all year, but this mirror's event_time was built on Toronto wall time, so between the second Sunday of March and the first Sunday of November it is one hour early. The delivery end is event_time + toIntervalSecond(timeZoneOffset(toTimeZone(event_time, 'America/Toronto')) + 18000); rows in the spring-forward hour cannot be placed. Toronto civil time is for display only.
Demand regions are not price zones. Published a day late: the latest hours are yesterday's.

Access

Need the full history of this dataset in Snowflake, Databricks or your own storage? Data services delivers it on a schedule.

Schema15

Column

Type

event_timeDateTime64(6, 'UTC')

ontario_demandNullable(Float64)

northwestNullable(Float64)

northeastNullable(Float64)

ottawaNullable(Float64)

eastNullable(Float64)

torontoNullable(Float64)

essaNullable(Float64)

bruceNullable(Float64)

southwestNullable(Float64)

niagaraNullable(Float64)

westNullable(Float64)

zones_totalNullable(Float64)

diffNullable(Float64)

ingested_atDateTime64(6, 'UTC')

Sample data

event_time	ontario_demand	northwest	northeast	ottawa	east	toronto	essa	bruce	southwest	niagara	west	zones_total	diff	ingested_at
2026-10-10 04:00:00.000000	13886	396	1335	844	807	4873	932	77	2839	518	1494	14114	228	2026-10-10 17:10:33.785263
2026-10-10 04:00:00.000000	13886	396	1335	844	807	4873	932	77	2839	518	1494	14114	228	2026-10-10 16:10:33.239365
2026-10-10 03:00:00.000000	14511	412	1410	900	858	5166	994	75	2969	547	1543	14873	362	2026-10-10 17:10:33.785263
2026-10-10 03:00:00.000000	14511	412	1410	900	858	5166	994	75	2969	547	1543	14873	362	2026-10-10 16:10:33.239365
2026-10-10 02:00:00.000000	15297	414	1398	961	925	5422	1059	78	3081	511	1629	15478	181	2026-10-10 17:10:33.785263
2026-10-10 02:00:00.000000	15297	414	1398	961	925	5422	1059	78	3081	511	1629	15478	181	2026-10-10 16:10:33.239365
2026-10-10 01:00:00.000000	16091	438	1369	1024	984	5776	1129	82	3276	555	1714	16345	254	2026-10-10 17:10:33.785263
2026-10-10 01:00:00.000000	16091	438	1369	1024	984	5776	1129	82	3276	555	1714	16345	254	2026-10-10 16:10:33.239365
2026-10-10 00:00:00.000000	16567	443	1312	1063	1024	5962	1177	86	3355	578	1764	16763	196	2026-10-10 17:10:33.785263
2026-10-10 00:00:00.000000	16567	443	1312	1063	1024	5962	1177	86	3355	578	1764	16763	196	2026-10-10 16:10:33.239365
2026-10-09 23:00:00.000000	16722	435	1260	1064	1031	6048	1189	92	3327	576	1835	16859	136	2026-10-10 17:10:33.785263
2026-10-09 23:00:00.000000	16722	435	1260	1064	1031	6048	1189	92	3327	576	1835	16859	136	2026-10-10 16:10:33.239365
2026-10-09 22:00:00.000000	16655	427	1260	1053	1010	5957	1127	93	3289	564	1917	16696	41	2026-10-10 17:10:33.785263
2026-10-09 22:00:00.000000	16655	427	1260	1053	1010	5957	1127	93	3289	564	1917	16696	41	2026-10-10 16:10:33.239365
2026-10-09 21:00:00.000000	16464	426	1224	1045	903	5990	1029	87	3263	563	1949	16480	16	2026-10-10 17:10:33.785263
2026-10-09 21:00:00.000000	16464	426	1224	1045	903	5990	1029	87	3263	563	1949	16480	16	2026-10-10 16:10:33.239365
2026-10-09 20:00:00.000000	15904	414	1192	986	721	5976	894	83	3168	554	1873	15860	-44	2026-10-10 17:10:33.785263
2026-10-09 20:00:00.000000	15904	414	1192	986	721	5976	894	83	3168	554	1873	15860	-44	2026-10-10 16:10:33.239365
2026-10-09 19:00:00.000000	16048	408	1164	1003	715	5936	801	74	3326	552	1778	15757	-291	2026-10-10 17:10:33.785263
2026-10-09 19:00:00.000000	16048	408	1164	1003	715	5936	801	74	3326	552	1778	15757	-291	2026-10-10 16:10:33.239365
2026-10-09 18:00:00.000000	15579	410	1153	1014	691	5998	789	66	3428	563	1728	15840	261	2026-10-10 17:10:33.785263
2026-10-09 18:00:00.000000	15579	410	1153	1014	691	5998	789	66	3428	563	1728	15840	261	2026-10-10 16:10:33.239365
2026-10-09 17:00:00.000000	15701	413	1172	988	527	6073	841	77	3320	571	1669	15652	-48	2026-10-10 17:10:33.785263
2026-10-09 17:00:00.000000	15701	413	1172	988	527	6073	841	77	3320	571	1669	15652	-48	2026-10-10 16:10:33.239365
2026-10-09 16:00:00.000000	15660	413	1273	950	512	6039	843	68	3352	557	1633	15642	-19	2026-10-10 17:10:33.785263

Coverage

No time-indexed data — coverage isn’t applicable to this dataset.

Related load data

Related load data
Dataset	Description
IESO Real-Time TotalsIESO · five-minute	IESO's real-time market totals: Ontario demand (ontario_load), market total load, total energy and losses, scheduled-off dispatchable load and the three reserve totals, with the report's flag. Observed only: no Ontario demand forecast is in the data, so a forecast peak or forecast demand cannot be answered from it.
7-Day Load ForecastPJM · hourly (7-day horizon)	PJM's seven-day-ahead hourly load forecast by forecast area, refreshed through the day. Rows are keyed by target time (event_time) with the issue time in evaluated_at_utc; take the latest vintage per target hour via an argMax over evaluated_at_utc. Forecast areas match the very-short-term feed (utility names, RTO_COMBINED for the system total). This is the table for tomorrow's peak and the week-ahead demand outlook. Source: PJM Market Data.
Actual Demand by RegionMISO · hourly	Observed hourly MISO demand in MW for the Central, North, and South sub-regions. Region labels are normalized to uppercase; this is regional operational load, not a local-resource-zone series.
Actual System LoadSPP · 5-minute	SPP's realized system-wide demand in MW at five-minute resolution, the actual-load counterpart to the short-term and mid-term load forecasts. Note that the feed republishes the same event_time on successive polls with a fresh ingested_at, so a read should collapse repeats on ingested_at before use.