> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.isoview.io/llms.txt.
> For full documentation content, see https://docs.isoview.io/llms-full.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.isoview.io/_mcp/server.

# Data Freshness

## Historical data availability

Historical forecasts available back to **January 1, 2026** via the `forecasted_by` parameter. Applies to both standard forecast and continuous endpoints.

Day-ahead backcasted forecasts available from **January 1, 2023** onward.

Historical observed data available from **January 1, 2022** onward via the `/region/{iso}/{metric}/actual` endpoint.

## Data update cadence

| Data type   | Update frequency | Notes                                                                                 |
| ----------- | ---------------- | ------------------------------------------------------------------------------------- |
| Regions     | As needed        | ISOs may add, modify, or remove regions over time. ISOview keeps definitions current. |
| Plants      | Monthly          | Capacity, coordinates, operational status, and county assignment.                     |
| Gas history | Enterprise only  | Historical natural gas price data requires an enterprise membership.                  |

For bulk historical data access or natural gas history, inquire about our [enterprise membership](https://isoview.io/contact) which includes priority support.