weather.us.alerts

US Weather Alerts

Active National Weather Service watches, warnings and advisories for a US point or state, with severity, timing and instructions. An empty list means none active right now.

Example answer

Ask

Are there any active weather warnings for this US location?

GET /v1/weather/us/alerts?lat=38.8977&lon=-77.0365

Eckari

{
  "query": {
    "lat": 38.8977,
    "lon": -77.0365,
    "state": null,
    "detail": "compact"
  },
  "items": [],
  "page": {
    "limit": 5,
    "offset": 0,
    "returned": 0,
    "total": 0,
    "has_more": false,
    "next_offset": null
  }
}

Source: National Weather Service
Freshness: Live
Price: $0.003

Version: 4.0.0
Transport: HTTP / MCP
Coverage: US

Use this when

Decide whether an active US weather warning affects a location before dispatching or travelling.
Are there any active weather warnings for this US location?
Is there a tornado warning, hurricane advisory or flood watch in this state?
You need severe weather alerts before dispatching a driver or crew.
You need alert severity, urgency and expiry to decide whether to act.
You need the official NWS alert text and safety instruction (detail=full).

Don't use this when

You need the forecast rather than alerts - use weather.us.forecast.
You need measured conditions - use weather.us.observation.
The location is outside the United States and its territories (returns UNSUPPORTED_REGION).
You need historical alert archives or alert polygons - not supported.

If the user has asked you to inspect a specific website, page or URL, use your browsing tool instead — this capability only returns the US National Weather Service API record.

Input

latnumberoptional

Latitude in decimal degrees (WGS84). Provide lat and lon together, or provide state.

lonnumberoptional

Longitude in decimal degrees (WGS84). Provide lat and lon together, or provide state.

statestringoptional

Two-letter US state, territory or NWS marine area code such as CA / TX / PR. Alternative to lat and lon; one of the two forms is required.

limitintegerdefault 5

Maximum number of active alerts to return, in the order NWS returns them. The default of 5 keeps the answer compact - a busy state can have dozens of active alerts, each covering tens of zones - and page.total always reports how many are active, so nothing is hidden.

offsetintegerdefault 0

Zero-based index of the first alert to return, for paging through the active set with limit. The whole active set is read in one upstream request and returned in that order, so a window over it is consistent.

detailstringdefault "compact"

compact (default) returns the fields an agent decides on. full adds the two NWS narrative members - description (the multi-paragraph WHAT/WHERE/WHEN/IMPACTS text, truncated at 2000 characters with description_truncated set) and instruction (the protective-action text) - which are written for a human reader and are several times the size of the rest of the alert.

What the result means

queryobject

The area actually queried, echoed so a batched caller can match answers to inputs.

itemsarray

Active alerts in the order the National Weather Service returns them (newest first, by the time the message was sent; Eckari does not re-sort), windowed by limit and offset. An empty array means no alert is active for the queried point or area right now - it is a valid answer, not an error.

pageobject

Canonical paging block over the active alert set. total is exact - the whole set is read in one request and page reports a window over it.

Provenance

Source: National Weather Service
Freshness: Live · read at request time, not cached
Region: US

Access

Over MCP: weather_us_alerts
Over HTTP: GET https://api.eckari.com/v1/weather/us/alerts
Price: $0.003 per call over x402. Account access $0.002 when that rail opens.