Japan AMeDAS Weather Observations (JMA official data)

Turn the Japan Meteorological Agency (JMA / 気象庁) AMeDAS network — Japan's ~1,300-station automated surface-observation grid (地域気象観測システム) — into clean, English-labelled records. This Actor reads JMA's own public bosai AMeDAS JSON (the same data that powers the live map on jma.go.jp) and restructures it: station names and prefectures resolved to English, [deg, min] coordinates converted to decimal degrees, wind directions decoded to English cardinals, and every measurement labelled with its unit.

No API key. No login. Public government open data.

Observations, not forecasts. This is the live-measurement sibling of Japan Weather Forecast & Warnings (JMA), which reads JMA's forecast and warning feeds. Use this Actor for what the weather is right now; use the forecast Actor for what it will be.

Quick start — verified input

Copy, paste, run. This exact input is verified on the platform (SUCCEEDED, items > 0):

{
  "mode": "latest",
  "prefecture": "Tokyo",
  "maxItems": 500
}

Running with no input at all also works (same defaults). prefecture is a dropdown of the 47 English prefecture names; via the API you may also pass the Japanese name ("東京都"), the JIS code ("13"), or common romanisations ("osaka-fu", "Ōsaka", "Tokyo-to"). For one specific station use {"mode": "by_station", "stationCode": "44132"}.

What you get

Pick a mode:

• latest — the most recent 10-minute snapshot for every reporting station nationwide (or filtered to a prefecture / list of stations). One record per station.
• by_station — the full 10-minute time series for the station(s) you name (the latest 3-hour file), including daily max/min temperature and peak gust. One record per timestep.
• stations — the AMeDAS station directory: code, names (EN / 漢字 / カナ), latitude, longitude, altitude, prefecture, and which elements each station observes.

Example output (latest, one station)

{
  "mode": "latest",
  "stationCode": "44132",
  "stationNameEn": "Tokyo",
  "stationNameJa": "東京",
  "prefectureCode": "13",
  "prefectureNameEn": "Tokyo",
  "latitude": 35.6917,
  "longitude": 139.75,
  "altitude": 25,
  "observedAt": "2026-08-26T04:20:00+09:00",
  "temperatureC": 26.9,
  "humidity": 89,
  "precipitation1hMm": 0,
  "windSpeedMs": 1.8,
  "windDirectionCode": 14,
  "windDirection": "Northwest",
  "sunshineHours": 0,
  "pressureHpa": 1006.8,
  "source": "気象庁 アメダス bosai JSON ... / Japan Meteorological Agency (JMA) AMeDAS surface-observation open data",
  "sourceUrl": "https://www.jma.go.jp/bosai/amedas/",
  "license": "出典：気象庁ホームページ（https://www.jma.go.jp/）。...",
  "retrievedAt": "2026-08-26T12:00:00.000Z"
}

Every record carries the four attribution fields (source, sourceUrl, license, retrievedAt).

Measured fields

temperatureC, humidity (%), precipitation10mMm / precipitation1hMm / precipitation3hMm / precipitation24hMm, windSpeedMs (10-min mean), windDirectionCode (JMA 1–16) + windDirection (English cardinal), sunshine10mMin / sunshineHours, snowDepthCm, pressureHpa, seaLevelPressureHpa, and (in by_station) gustSpeedMs + gustDirection. Any value a station does not measure — or that is missing at that moment — is null (never fabricated).

Input

Field	Description
mode	latest (default), by_station, or stations. Case-insensitive.
prefecture	Optional filter for latest / stations: one of the 47 prefectures — English ("Tokyo"), Japanese ("東京都"), or JIS code ("13").
stationCode	5-digit AMeDAS code(s), comma-separated or as a list (e.g. "44132" Tokyo, "62078" Osaka). Required for by_station; optional filter for latest.
maxItems	Max records to output, 1–2000 (default 500).
maxApiRequests	Hard per-run request cap, 1–60 (default 12).
proxyConfiguration	Apify proxy; default is a direct connection.

Station codes live in amedastable.json, or run mode stations to list them. A station's prefecture is derived from the leading two digits of its code via JMA's own prefecture-block table.

Values are validated before the first request; an invalid value fails the run immediately with a message that lists the valid values.

Common input mistakes

Mistake	Correct
"prefecture": "Osaka-shi" / "Yokohama" (a city)	"prefecture": "Osaka" / "Kanagawa" — prefectures only
"mode": "by_station" without stationCode	add "stationCode": "44132" — or use "mode": "latest" with a prefecture
"stationCode": "Tokyo"	a 5-digit code: "44132" (find it with "mode": "stations")
"stationCode": "4413" (4 digits)	"44132" — codes are exactly 5 digits
"mode": "observations" / "current"	"mode": "latest" (these two aliases are accepted, other words are not)
"maxItems": "all"	a number, e.g. 500

Empty results?

The run completes with 0 items (and a warning in the log, not a failure) when the filter matches no station: a prefecture + stationCode pair that do not belong together (e.g. "prefecture": "Tokyo" with "stationCode": "62078" Osaka), or a station code that JMA has retired. Also note that latest only lists stations that reported in the most recent 10-minute slot — a station under maintenance is absent until it reports again. Drop the extra filter or take a current code from mode stations.

How it fetches (politeness)

A single sequential connection, ≥ 1.2 s between requests, exponential backoff on 429/5xx, and a hard per-run request budget. A latest run makes only ~3 requests (station table + latest-time pointer + one all-station map). The Actor never evades a block: on a persistent 429 it fails visibly rather than hammering the server.

Attribution, terms & disclaimer

• Public open data. JMA website content is provided under the 公共データ利用規約（第1.0版）(Public Data License 1.0), which permits copying, adaptation, and commercial use provided the source is displayed. The required credit — 出典：気象庁 — is embedded verbatim in every record's license field. See the JMA terms of use.
• Unofficial — not affiliated. This is an independent tool. It is not affiliated with, endorsed by, or operated by the Japan Meteorological Agency.
• Edited / adapted. Per the terms, note that this tool edits and adapts JMA data (structuring Japanese data into English); it does not present the data as if produced by JMA. It redistributes JMA-published observation values; it is not a forecasting service (気象業務法第17条) and does not itself issue warnings (第23条). For life-safety decisions, always consult the official JMA site.
• Your responsibility. You are responsible for your own compliance with the JMA website terms and any applicable law (including data-protection law such as the GDPR) in how you use the output. The data is aggregate meteorology and contains no personal data.

Search terms

japan amedas data · japan weather observation api · japan temperature data english · jma amedas · japan rainfall data · japan wind observation · japan weather station data · tokyo temperature api · japan meteorological observations · 気象庁 アメダス json