canonical: https://jentic.com/apis/ornl.gov/daymet

# Ornl Gov Daymet Single Pixel Extraction Tool API

Jentic publishes the only available OpenAPI specification for Daymet Single Pixel Extraction Tool API, keeping it validated and agent-ready. Daymet is a NASA-funded gridded climate dataset hosted by Oak Ridge National Laboratory's DAAC, providing daily weather variables across North America at one-kilometre resolution from 1980 to the near-present. The Single Pixel Extraction Tool exposes four endpoints to extract a time-series at a given latitude/longitude for variables such as minimum and maximum temperature, precipitation, vapor pressure, shortwave radiation, snow water equivalent, and day length. It is suitable for hydrology, agriculture, and climate-impact modelling that needs reproducible historical weather at point locations.

## For AI agents

Extract daily Daymet climate variables for any North American latitude/longitude point and visualize or download the resulting time-series.

## Scope

Does not provide forecasts, real-time observations, or non-North-American coverage - use for historical Daymet single-pixel extraction only.

## Capabilities

- Extract a daily climate time-series at a latitude/longitude through GET `/api/data` with a year range and variable list
- Generate a quick visual preview of the requested variables via GET /preview
- Send the extracted dataset to a saved-data endpoint with GET `/send/saveData` for downstream retrieval
- Render an interactive visualization of the time-series via GET /visualize
- Pull historical daily Tmin, Tmax, precipitation, and radiation for a research site without hosting the full Daymet grid

## Use cases

### Reproducible Climate Inputs for Hydrology Models

Hydrologists running watershed models often need point-scale daily forcings. GET `/api/data` returns a CSV time-series for the requested variables at a coordinate, ensuring every model run uses the same Daymet grid version and avoiding ad hoc weather-station gap filling.

Example prompt: GET `/api/data`?lat=35.96&lon=-83.92&vars=tmin,tmax,prcp&year=1980-2024 and feed the CSV into the hydrology model's forcings module.

### Crop Phenology and Agricultural Modelling

Agronomists modelling crop development can pull daily Tmin, Tmax, and day length from Daymet at a field-level coordinate. The four endpoints cover both data extraction and visual sanity checks, helping verify that a long time-series has no obvious anomalies before it feeds a growing-degree-day model.

Example prompt: GET `/api/data` with vars=tmin,tmax,dayl for a field coordinate, then GET /visualize to confirm continuity before feeding into the GDD calculator.

### Climate Impact Risk Assessment

Insurers and ESG teams assessing climate risk at specific assets can use Daymet to build historical baselines for precipitation extremes and temperature anomalies. The free, citable dataset removes licensing friction for reports requiring auditable provenance.

Example prompt: GET `/api/data`?lat=&lon=&vars=prcp&year=1980-2024 for each asset coordinate and compute the 99th-percentile daily precipitation.

### Agent-Driven Weather Lookups via Jentic

Research and analytics agents can pull historical Daymet weather for any North American coordinate through Jentic without configuring the ORNL endpoint manually. Jentic exposes the four operations by intent and handles parameter formatting.

Example prompt: Use Jentic to search 'extract historical weather for a coordinate', load the GET `/api/data` schema, and execute with the lat/lon and variable list.

## Key endpoints

| Method | Path | Description |
| --- | --- | --- |
| GET | `/api/data` | Extract a daily climate time-series at a coordinate |
| GET | `/preview` | Quick preview of the requested variables |
| GET | `/send/saveData` | Persist the extraction for later retrieval |
| GET | `/visualize` | Render an interactive visualization |

## Key resources

- **Data Extraction** — Pull a daily Daymet time-series at a coordinate
- **Preview** — Lightweight preview of the requested variables
- **Save Data** — Persist the extraction result for later retrieval
- **Visualize** — Render an interactive plot of the time-series

## Why Jentic

- **Setup:** The Daymet Single Pixel Extraction Tool API needs no credentials, but wiring it by hand still means formatting the coordinate, variable, and year query parameters and handling the extraction response yourself. Through Jentic you install once, import Daymet from the API Directory, and your agent calls it through the same audited path as your credentialed APIs.
- **Permission scoping:** You choose which Daymet operations the agent may call, so you can limit it to the operations it needs, such as extracting historical data for a coordinate, while the preview, save, and visualize operations stay out of the allowed set unless you add them.
- **Credential handling:** Daymet requires no credential, so there is nothing to store, and Jentic routes each call through your own Jentic One instance for unified logging and rate management alongside your credentialed APIs.
- **Discovery method:** Agents search Jentic by intent such as 'extract historical weather for a coordinate', and Jentic returns the matching Daymet operation with its input schema and parameter formatting so the agent calls the right endpoint without browsing the reference docs.

## Related APIs

- **NOAA API** — NOAA's APIs provide weather-station and gridded forecast data as a US federal alternative to Daymet's gridded historical record.
- **OpenWeatherMap API** — OpenWeatherMap offers global current and forecast weather APIs, including some historical history endpoints behind paid plans.
- **WeatherAPI** — WeatherAPI provides forecast and astronomy endpoints that pair with Daymet's historical baseline.

## FAQ

### Why is there no official OpenAPI spec for Daymet Single Pixel Extraction Tool API?

ORNL DAAC publishes Swagger documentation for Daymet but not a maintained, agent-ready OpenAPI document. Jentic generates and maintains this spec so that AI agents and developers can call Daymet Single Pixel Extraction Tool API via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.

### What authentication does the Daymet API use?

The single-pixel extraction endpoints are public and do not require authentication in this spec. Through Jentic the request is still routed via the platform so usage is logged consistently with other agent operations.

### Can I extract daily precipitation for a coordinate with the Daymet API?

Yes. GET `/api/data` accepts lat, lon, and a vars list including prcp (precipitation) along with tmin, tmax, dayl, srad, swe, and vp, returning a daily CSV time-series.

### What are the rate limits for the Daymet API?

ORNL DAAC does not declare numeric rate limits in the spec. Heavy users are encouraged to download bulk Daymet files instead - confirm acceptable single-pixel volumes with the DAAC if you plan to extract thousands of points per day.

### How do I extract a Daymet time-series through Jentic?

Search Jentic for 'extract historical weather for a coordinate', load the GET `/api/data` schema, and execute with lat, lon, year range, and the comma-separated variable list.

### Is the Daymet API free?

Yes. Daymet is funded by NASA and distributed without charge through ORNL DAAC for research and operational use. Citation of the dataset is requested for published work.

### Can I limit what my agent is allowed to do with the Daymet Single Pixel Extraction Tool API?

Yes. Because Jentic One runs self-hosted, your own rules decide which Daymet operations and credentials the agent may use. You can allow only the operations it needs, such as GET `/api/data` to extract a historical time-series for a coordinate, while keeping the preview, save-data, and visualize operations out of the allowed set unless you add them. The agent can call only the operations you have permitted, so it cannot reach beyond that scope.