[Docs](/docs) / Weather

# Weather

Read National Weather Service forecasts and active alerts for a US location, with source links, units and update times.

## Call it

Use an agent API key, including a tenant sub-key. Management credentials cannot call tools. Available tools appear on your combined MCP endpoint when switched on.

```
https://mcp.deep.navy/mcp
```

Check [Tools in the dashboard](/dashboard/tools) for current availability. Your MCP client reads the current input and output schemas from the server. These are on-demand provider lookups; source freshness and coverage differ by dataset. For API-key provisioning, see the [platform API guide](/docs/platform); for failures and retries, see [limits and errors](/docs/limits).

## Coverage and interpretation

Forecasts cover US land locations supported by the National Weather Service. These tools do not provide global weather or historical observations.

Forecast periods can be hourly or approximately twelve hours. Preserve the returned time zone, units and forecast times when comparing periods.

Alerts are active notices at the requested point. Read each alert’s affected area, severity, validity period and instructions, and follow the official source for updates. A truncated result indicates additional alerts exist.

## weather_forecast

Fetch forecast periods for latitude and longitude. Set hourly for hourly periods and choose US or SI units.

- latitude and longitude are required decimal coordinates (latitude −90 to 90, longitude −180 to 180). The location must have an NWS land forecast. Global and marine forecasts are not supported.
- hourly defaults to false. units accepts us (default, Fahrenheit) or si (Celsius). limit defaults to 14 and accepts 1–48 periods, bounded by the provider’s available forecast horizon.
- Read periods with their startTime/endTime offsets, temperatureUnit and response timeZone. An absent precipitationProbability means unknown, not zero. truncated means the limit excluded available periods; increase limit within the maximum. There is no pageToken or historical-date parameter.

## Example request: `weather_forecast`

Arguments for an MCP tools/call request. The values returned depend on the source’s current data.

```
{
  "name": "weather_forecast",
  "arguments": {
    "latitude": 38.8977,
    "longitude": -77.0365,
    "hourly": false,
    "units": "us",
    "limit": 14
  }
}
```

Direct HTTP API: POST the argument object to `deepnavy.weather.v1.WeatherService/GetForecast`. The response is the protobuf JSON body, without an MCP envelope. Set `DEEPNAVY_KEY` in your environment before running:

```
curl --fail-with-body --request POST 'https://api.deep.navy/deepnavy.weather.v1.WeatherService/GetForecast' \
  --header "Authorization: Bearer $DEEPNAVY_KEY" \
  --header 'Content-Type: application/json' \
  --header 'Connect-Protocol-Version: 1' \
  --data '{"latitude":38.8977,"longitude":-77.0365,"hourly":false,"units":"us","limit":14}'
```

## weather_alerts

Fetch active weather alerts at a point, including affected areas and official instructions.

- latitude and longitude are required. limit defaults to 20 and accepts 1–100 active alerts for the point. The tool requests actual alerts, excluding exercises and tests.
- Read alerts, source.sourceUrl and updatedAt. Empty alerts means NWS returned no active notices for this point, not a safety guarantee. Check severity, certainty, urgency, affectedZones and expiry; follow the official instructions. If truncated is true, increase limit up to 100; this tool has no cursor pagination.

## Example request: `weather_alerts`

Arguments for an MCP tools/call request. The values returned depend on the source’s current data.

```
{
  "name": "weather_alerts",
  "arguments": {
    "latitude": 38.8977,
    "longitude": -77.0365,
    "limit": 20
  }
}
```

Direct HTTP API: POST the argument object to `deepnavy.weather.v1.WeatherService/GetAlerts`. The response is the protobuf JSON body, without an MCP envelope. Set `DEEPNAVY_KEY` in your environment before running:

```
curl --fail-with-body --request POST 'https://api.deep.navy/deepnavy.weather.v1.WeatherService/GetAlerts' \
  --header "Authorization: Bearer $DEEPNAVY_KEY" \
  --header 'Content-Type: application/json' \
  --header 'Connect-Protocol-Version: 1' \
  --data '{"latitude":38.8977,"longitude":-77.0365,"limit":20}'
```

## Sources, documentation and reuse

Source: NOAA National Weather Service. The API documentation permits use of its data for any purpose. Preserve the official alert and forecast links; availability and updates depend on NWS.

- [National Weather Service homepage](https://www.weather.gov/)
- [API documentation and usage policy](https://www.weather.gov/documentation/services-web-api)
- [OpenAPI reference](https://api.weather.gov/openapi.json)
- [Official active alerts](https://www.weather.gov/alerts)

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This is the Markdown copy of https://deep.navy/docs/weather.