CAISO Hourly Actual Load

Actual hourly electricity demand in CAISO, one row per hour with a system total and one column per TAC area.

Load data CAISO market

Query with the agent

Native record

one row per operating hour, wide by sub-area

hourly publication cadence

Evidence

Observed market data

Published observations from the named source

Time basis

Interval-start records

UTC · event_time

Overview

75,689 hours, 2018-01 to now. Columns: system_mw plus pge_mw, sce_mw, sdge_mw, vea_mw, mwd_mw. system_mw is CAISO's own CA ISO-TAC total. The five TAC areas are the CAISO balancing area's own partition. Wide rather than long, so "load right now" and "the 5 TAC area shares of it" are one row, not 6. Every market's load table in this catalog shares the system_mw column and the same hourly grain, so a cross-market demand comparison needs no reshaping.

Query contract

One row is the canonical hourly value; the refresh already collapsed the source's restatements. Read the hour you want and use its columns together.

Analysis rules

Take every value for one hour from that hour's single row. Never combine a system total from one hour with area values from another.
An area's share of demand is <area>_mw / system_mw within the same row. Do not sum the 5 area columns and system_mw together — that double-counts the whole market.

Related analysis

forecast error for a delivered hour · join on event_time, one forecast vintage at a time

Interpretation

This is CAISO load only. The raw caiso.load_actual feed also carries 33 neighbouring balancing authorities (BPAT, LADWP, NEVP, PACW and so on); those are deliberately not in this table, and a question about them must go to caiso.load_actual.
Hourly values are interval averages, not instantaneous readings. An hourly average and a five-minute snapshot at the same timestamp are different quantities and will differ; that is not an error in either.

Access

Query from your own tools

Use the guarded HTTP endpoint directly, or connect an MCP client and load the dataset contract with describe_data before calling query_data.

CAISO MCP API reference

HTTP endpoint

POST /api/v1/datasets/caiso_load/query

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

Schema7

Column

Type

event_timeDateTime64(6, 'UTC')

system_mwNullable(Float64)

pge_mwNullable(Float64)

sce_mwNullable(Float64)

sdge_mwNullable(Float64)

vea_mwNullable(Float64)

mwd_mwNullable(Float64)

Sample data

event_time	system_mw	pge_mw	sce_mw	sdge_mw	vea_mw	mwd_mw
2026-10-12 06:00:00.000000	22889	9789	10620	2249	54	177
2026-10-12 05:00:00.000000	24062	10396	11078	2357	54	177
2026-10-12 04:00:00.000000	25189	10994	11466	2498	54	177
2026-10-12 03:00:00.000000	25564	11326	11398	2607	56	177
2026-10-12 02:00:00.000000	26257	11675	11677	2669	58	178
2026-10-12 01:00:00.000000	26010	11592	11543	2640	57	178
2026-10-12 00:00:00.000000	24919	10727	11337	2624	54	177
2026-10-11 23:00:00.000000	25672	9912	12634	2896	53	177
2026-10-11 22:00:00.000000	26147	8938	13954	3025	53	177
2026-10-11 21:00:00.000000	26843	8483	15081	3062	53	164
2026-10-11 20:00:00.000000	27084	8327	15266	3273	53	165
2026-10-11 19:00:00.000000	26607	8062	14924	3404	53	164
2026-10-11 18:00:00.000000	25730	7669	14631	3216	50	164
2026-10-11 17:00:00.000000	24947	8269	13498	2964	52	164
2026-10-11 16:00:00.000000	24384	9019	12645	2503	50	167
2026-10-11 15:00:00.000000	22906	9264	11102	2317	46	177
2026-10-11 14:00:00.000000	22167	9527	10202	2215	46	177
2026-10-11 13:00:00.000000	21782	9354	10031	2173	46	178
2026-10-11 12:00:00.000000	21240	9094	9786	2136	46	178
2026-10-11 11:00:00.000000	21276	9084	9795	2173	45	179
2026-10-11 10:00:00.000000	21401	9100	9867	2211	45	178
2026-10-11 09:00:00.000000	22053	9391	10162	2274	47	179
2026-10-11 08:00:00.000000	23311	9737	10903	2442	49	180
2026-10-11 07:00:00.000000	24215	10143	11276	2566	49	181
2026-10-11 06:00:00.000000	25065	10377	11940	2511	58	179

Coverage

100.0% complete0 gap days3,207 days with data

Show coverage history

Coverage: 100.0%Days with data: 3,207Gaps: 0

2026

2025

2024

2023

2022

2021

2020

2019

2018

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Related load data

Related load data
Dataset	Description
CAISO Day-Ahead Load ForecastCAISO · hourly (day-ahead run)	CAISO's day-ahead demand forecast, one row per forecast hour with a system total and one column per TAC area. 75,727 hours, 2018-01 through the next delivery day. Column-for-column identical to CAISO Load (caiso_load) on purpose: system_mw, pge_mw, sce_mw, sdge_mw, vea_mw, mwd_mw. Forecast-versus-actual is therefore a plain join on event_time with no reshaping on either side. CAISO publishes no issue-time column for this feed, so there is no vintage axis here — this is the day-ahead market run for each hour, not a curve of successive forecasts. CAISO's other horizons (two-day, seven-day, real-time) live in caiso.load_forecast_horizons and only begin in May 2026.
Five-Minute Demand OutlookCAISO · 5-minute	CAISO system demand, day-ahead and hour-ahead demand forecasts, and demand response from the live demand Outlook. Every capture is retained, with Pacific snapshot date and DST ambiguity flags.
Load ActualsCAISO · hourly	Hourly actual electricity demand from CAISO OASIS, reported for the CAISO system total and TAC load areas such as PG&E, SCE, and SDG&E. This settlements-grade series is published after the operating interval rather than as a live five-minute reading. It supports forecast benchmarking, historical load shape, and aligned hourly net-load analysis. The official source is CAISO OASIS.
Load Forecast HorizonsCAISO · 5-minute forecast	CAISO load forecasts for the system and TAC load areas. The RTM five-minute label is the rolling VSTLF forecast used for each real-time dispatch operating interval, not a day-ahead peak forecast. event_time is the delivery interval and source_time is the publication time. For an honest historical forecast comparison, select the last source_time at or before event_time; for a forward interval select the latest source_time available at the analysis cutoff. The public source is CAISO OASIS.