Planetary K-index of geomagnetic activity, past week

At a glance

Publisher

NOAA Space Weather Prediction Center · homepage

Category

Weather observations & forecasts

Jurisdiction

United States (federal)

Publisher updates

Every three hours, as each period is estimated

SourceFinch checks

Daily by default

Records per run

63 in the latest run

Record key

time_tag

Acquired from

Publisher's public API: https://services.swpc.noaa.gov/products/noaa-planetary-k-index.json

Recipe

v1.0.0, approved October 12, 2026

Verified since

October 12, 2026

Last green run

October 12, 2026

What the data contains

The planetary K-index (Kp) is the standard measure of global geomagnetic disturbance, on a scale from 0 (quiet) to 9 (extreme storm); NOAA's G1 to G5 geomagnetic storm scale starts at Kp 5. NOAA's Space Weather Prediction Center (SWPC) publishes Kp for every three-hour UTC period, estimated in near real time from a network of ground magnetometers, as a public JSON product. This source reads the product on each daily run and makes one record per three-hour period (about 60 records covering the past week), keyed by the period's start time, with Kp as a number, the running a-index (the equivalent linear amplitude) and the number of stations that contributed. The most recent periods are preliminary and can be revised, which a monitor reports as changes. A period leaving the seven-day window is not a deletion. The data describes the geomagnetic field and contains no personal data. SourceFinch is independent of NOAA.

Fields and types

Every record has these fields. The key field time_tag identifies a record across runs, so changes are reported field by field.

Sample output

The first 5 of 63 records from SourceFinch's own run on October 12, 2026, exactly as delivered.

[
  {
    "kp": 4,
    "time_tag": "2026-10-05T00:00:00",
    "a_running": 27,
    "station_count": 8
  },
  {
    "kp": 5.33,
    "time_tag": "2026-10-05T03:00:00",
    "a_running": 56,
    "station_count": 8
  },
  {
    "kp": 2.33,
    "time_tag": "2026-10-05T06:00:00",
    "a_running": 9,
    "station_count": 8
  },
  {
    "kp": 3.33,
    "time_tag": "2026-10-05T09:00:00",
    "a_running": 18,
    "station_count": 8
  },
  {
    "kp": 2.67,
    "time_tag": "2026-10-05T12:00:00",
    "a_running": 12,
    "station_count": 8
  }
]

Evidence behind every value

• Each run keeps the publisher's exact response, hashed with SHA-256. This sample came from a response with hash 6b64fe5842e07542f35b8ba1b7c68394c0e1efa3666f4fbec5af17fb15ca0783.
• Every value records where it came from in that response: a JSON Pointer into the retained capture.
• Each run gets a signed manifest (Ed25519) timestamped by an RFC 3161 authority: this run's manifest hash is 589253905428612947b9cc438f6093142cd10c75e212261ee3f6b7ad5d84d17d, timestamped October 12, 2026.
• The compliance state at capture is recorded with the evidence: robots.txt hash and verdict, AI-preference signals, crawler identity and the usage rights below.
• Download any run as an evidence bundle (WACZ) and check it offline, without trusting SourceFinch: sourcefinch verify-bundle run.wacz.

Terms posture and usage rights

The National Weather Service disclaimer, which covers the Space Weather Prediction Center, states that information on its sites is in the public domain unless specifically noted and may be used without permission, with credit to the issuing office requested; users must not imply endorsement. services.swpc.noaa.gov serves no robots.txt (HTTP 404), which RFC 9309 treats as allowing access, and the product needs no key.

NOAA Space Weather Prediction Center. SourceFinch is independent of and not endorsed by NOAA.

Usage rights travel with every record SourceFinch delivers (API, exports, webhooks and evidence bundles). They are our documented understanding of the publisher's stated terms, not legal advice.

Reliability

Runs, last 30 days

1

Green

100%

Failed

0

Median run time

0.9 s

Latest run

success, October 12, 2026

Measured on completed runs of this recipe version across SourceFinch, anonymized, within a rolling 30-day window. First successful observation: October 12, 2026. A new recipe has only the history collected since that date; this is not a 30-day uptime guarantee.

Use it

Every surface creates the same monitor from this Verified recipe. Monitors keep record history, report field-level changes and deliver by webhook, export or email. You confirm you have the right to collect the source (rights: true).

{
  "schema": "sourcefinch/source@1",
  "name": "Planetary K-index of geomagnetic activity, past week",
  "url": "https://services.swpc.noaa.gov/products/noaa-planetary-k-index.json",
  "recipe": {
    "mode": "http",
    "format": "json",
    "items": "[*]",
    "fields": {
      "kp": "Kp",
      "time_tag": "time_tag",
      "a_running": "a_running",
      "station_count": "station_count"
    },
    "required": [
      "time_tag",
      "kp"
    ],
    "types": {
      "a_running": "integer",
      "kp": "number",
      "station_count": "integer",
      "time_tag": "datetime"
    }
  },
  "schedule": "daily",
  "key_field": "time_tag"
}

{
  "name": "Planetary K-index of geomagnetic activity, past week",
  "url": "https://services.swpc.noaa.gov/products/noaa-planetary-k-index.json",
  "recipe": {
    "mode": "http",
    "format": "json",
    "items": "[*]",
    "fields": {
      "kp": "Kp",
      "time_tag": "time_tag",
      "a_running": "a_running",
      "station_count": "station_count"
    },
    "required": [
      "time_tag",
      "kp"
    ],
    "types": {
      "kp": "number",
      "time_tag": "datetime",
      "a_running": "integer",
      "station_count": "integer"
    }
  },
  "key_field": "time_tag",
  "schedule": "daily",
  "rights": true,
  "catalog": {
    "slug": "noaa-swpc-planetary-k-index",
    "version_id": "2cce2ac7-6f95-4865-b3b2-ae63483865c4"
  }
}

# the Verified entry (fields, recipe, sample, terms) as JSON
curl https://sourcefinch.com/v1/catalog/noaa-swpc-planetary-k-index -H "Authorization: Bearer $SOURCEFINCH_API_KEY"

# create the monitor from source.json (below)
curl -X POST https://sourcefinch.com/v1/sources \
  -H "Authorization: Bearer $SOURCEFINCH_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d @source.json

# then run it now (later runs follow the schedule)
curl -X POST https://sourcefinch.com/v1/sources/$SOURCE_ID/runs \
  -H "Authorization: Bearer $SOURCEFINCH_API_KEY" \
  -H "Idempotency-Key: $(uuidgen)"

sourcefinch login
sourcefinch catalog get noaa-swpc-planetary-k-index --source-json > source.json
sourcefinch sources create --file source.json
sourcefinch runs create $SOURCE_ID --wait
sourcefinch records $SOURCE_ID

import { SourceFinch } from "@sourcefinch/sdk";

const sf = new SourceFinch({ apiKey: process.env.SOURCEFINCH_API_KEY });
const entry = await sf.catalog.get("noaa-swpc-planetary-k-index");
const source = await sf.sources.create({
  catalog: { slug: entry.slug, version_id: entry.recipe.version_id },
  name: entry.name.slice(0, 100),
  url: entry.acquisition_path.endpoint,
  recipe: entry.recipe.definition,
  key_field: entry.recipe.key_field,
  schedule: entry.recipe.schedule,
  rights: true, // you confirm you have the right to collect this source
});
const run = await sf.runs.wait((await sf.runs.create(source.id)).id);
console.log(run.status);

claude mcp add --transport http sourcefinch https://sourcefinch.com/mcp

# then ask your agent:
"Use SourceFinch to monitor Planetary K-index of geomagnetic activity, past week: get_catalog_source noaa-swpc-planetary-k-index,
then create_source with its create_source_args (dry run first), then run_source."

Pricing

Each check is one run, whatever the number of records, and failed runs are free. On its default daily schedule this source uses about 30 runs a month, which fits the Free plan's 300 runs. It uses HTTP acquisition, so no browser runs are needed. See plans.

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