Returns the time series of one or more data catalog products at one location: the public, catalog-governed door to stored model and analysis data. Any grid or snapshot product that GET /v1/catalog lists qualifies, for example hrrr_surface, nbm_conus, gfs_surface, rtma_conus, mrms_qpe_01h_pass2_conus or astro. Variables are named by their catalog standard_name.

Experimental (x-stability: experimental): excluded from the 90-day breaking-change commitment while the grammar settles. units is required with no default while experimental.

Selection

product with var (repeatable; omit var for every variable of the product), or select=product:var (repeatable or comma-joined, at most 25) to read several products. An unknown product or variable is a 404. A catalog product that is public but not served by this route (an MCP-only product, or a REST product that is not a grid or snapshot) is a 404 when it is the only selection, and a not_public element beside a servable one.

Time

At most one time word, and it is optional:

• hours (1-384) takes its direction from the product's catalog product_type: forward from now for a forecast, backward from now for an analysis. With run, it counts from the run's initialization time. Rolling windows are rounded out so the frame covering now is included: a forecast starts at now floored to the product's catalog step (the UTC day for a daily product such as nbm_daily_temps, the last 00/06/12/18Z for a 6-hourly model such as aifs_single_surface, the last 5-minute mark for the PT5M nowcast, the hour for an hourly model), an analysis at now less hours rounded down to 5 minutes, and both end rounded up to 5 minutes.
• start and end (RFC 3339, at most 16 days apart), applied exactly as given: a daily row stamped at 00:00Z is outside a window that starts later that day.
• Neither: an analysis returns its latest frame and a forecast the next 24 h, rounded out as above (24 h from the run's initialization time with run).

A product with no product_type, or a climatology such as climate_normals_conus, requires start and end. run (RFC 3339) pins a forecast model cycle and composes with either time word; it is a 400 on a product that is not a forecast. step, stats, view, fields and format are reserved and return 400 for now; at is not a word of this route (use GET /v1/point for the latest value).

astro is an analysis whose rows run through about 14 days ahead, so with no time word it returns the newest row and hours looks back from now; pass start and end for specific days.

mrms_radar_nowcast_conus is a forecast served from one nowcast run, the newest whose frames (5 to 60 minutes after the run) reach the window, and run names it. Frames of that run outside the window are dropped. A past window is not stitched across runs, so a window no run reaches is unavailable. Observed radar history comes from mrms_reflectivity_conus and the MRMS QPE products such as mrms_qpe_01h_pass2_conus.

Units and raw values

units is si, metric or imperial. si serves stored values (K, m/s, mm, Pa, percent, and the stored SI unit for anything else). The chosen system is echoed at the top level and each element's units names every variable's unit; a percentage is always labelled percent. Values without a display unit are served raw, as stored, with no decode: astro sun and moon times are seconds after the row's UTC midnight (they can be negative or above 86400), moon values are x1000, and day_length -1 means no event. GET /v1/catalog/{product_id} describes each variable's encoding.

Coverage

Coverage is the 50 US states and DC, decided on the point's state (Canada, Mexico and open water inside a model grid are outside it). On GET /v1/series an in-range point outside it returns 404 outside-coverage with next_steps, as GET /v1/point does; global products (GFS, AIFS, astro, uv_index, ...) are not served there either. In POST /v1/series/batch such a location is an out_of_domain element, as is a location the check could not reach within its time limit (retry it; the lookup carries on and caches). A point that no selected product (nor a related one) serves is an out_of_domain element without the state check, since nothing would be served there.

Envelope

series[] holds one element per (product, location), in request order and column-oriented: times[] (RFC 3339 UTC), values per variable aligned with times[], and run when every frame shares one model run, else runs[] aligned with times[]. Each element has a status: ok; unavailable for an empty window; out_of_domain outside the product's catalog coverage[] or outside the 50 US states and DC (global products included), with related naming a sibling product that covers the point when one exists (there is no automatic switch); not_public. partial and entitlement_required are reserved. data_age_seconds and freshness_status match GET /v1/catalog?include=freshness; with run, both describe the pinned run (its age, and fresh or stale against the product's freshness budget; a product tracked in several stores uses the strictest). meta.timezone is the location's IANA zone (null when it cannot be resolved in time, or when no selected product covers the location). meta.sources[] carries each source's attribution and license; show the attribution where the license requires it (ECMWF AIFS is CC BY 4.0).

Density

limit caps frames per element (default 168, max 744). When it cuts any element, truncated is true and next_cursor resumes every element where it stopped: send it back as cursor with the same parameters (a cursor sent with other parameters is a 400). The cursor keeps the window page 1 resolved, so a rolling window does not move while paging. Each element pages independently; one that has finished returns no frames on later pages and keeps the status it had.

Caching

Cache-Control: max-age=N, stale-while-revalidate=N with N the smallest selected product cadence clamped to 60-3600 s, public for first-party keys and private for partner keys. An element's meta.timezone may be null when the timezone lookup is unavailable or slow; the response is then sent with Cache-Control: no-store, as it is when the timezone comes from a temporarily degraded or fallback lookup.

Auth and cost

Standard sw-api Bearer auth and rate limits apply. Cost class data, weight 1 per request: products, variables, hours and limit never change it.

{
  "meta": {
    "sources": [
      {
        "id": "hrrr",
        "attribution": "Data provided by NOAA/NWS",
        "license": "public_domain"
      }
    ]
  },
  "series": [
    {
      "product": "hrrr_surface",
      "related": "hrrr_alaska_surface",
      "meta": {
        "timezone": "America/Chicago"
      }
    }
  ]
}