Looks up Japan Meteorological Agency (JMA, 気象庁) area codes for a place in Japan. Accepts kanji (東京都, 札幌市, 渋谷区), kana (さっぽろ, シブヤ), romaji/English (Sapporo, Shibuya, Tokyo) or a JMA code. Returns ranked matches with their level (office = prefecture-level forecast district 府県予報区; class10 = sub-region 一次細分区域; class15 = local area; class20 = municipality 市区町村; center = regional block such as 北海道地方), the hierarchy path, and office_code, the code jma_get_forecast and jma_get_warnings use. You can usually pass a place name straight to those tools; call this first when a name is ambiguous (府中 exists in Tokyo and Hiroshima) or to show the user which area was meant. No API key needed.

Weather forecast from the Japan Meteorological Agency (JMA, 気象庁) for a place in Japan. Returns: today and the next 2 days per sub-region (weather text, wind, wave height in metres, precipitation chance in % for each 6-hour block, morning low and daytime high in °C at observation stations); a 7-day outlook (weather, precipitation chance %, reliability A=high/B=fair/C=low, low/high °C with the likely range, 30-year climate normals); and the forecaster's written overview. JMA issues forecasts per prefecture-level office around 05:00, 11:00 and 17:00 JST. Naming a municipality narrows the result to its sub-region. All times are JST (+09:00). Weather, wind and wave text is Japanese as JMA issued it; weather_en is an English label for each weather code.

Weather warnings and advisories (気象警報・注意報) in effect now, from the Japan Meteorological Agency (JMA), for a place in Japan. Uses the warning system JMA introduced on 2026-05-28: advisory 注意報 < warning 警報 < urgent warning 危険警報 < emergency warning 特別警報; heavy rain, landslide and storm surge also carry an alert level 2–5 (警戒レベル). Returns the distinct warnings in effect (severity, alert level, how many sub-regions and municipalities), each affected area with its warnings and extra hazards (e.g. 竜巻 tornado, ひょう hail, うねり swell), and JMA's Japanese headline text. An empty in_effect list means no warning or advisory is in effect for that area. Naming a municipality narrows the result to it.

Recent earthquakes in and around Japan from the Japan Meteorological Agency (JMA) feed, newest first (the feed covers roughly the last few weeks). Each item: origin time (JST), epicenter name in Japanese and English with latitude/longitude and depth in km, JMA magnitude (Mj), maximum seismic intensity on the JMA 震度 scale (1, 2, 3, 4, 5- = 5弱, 5+ = 5強, 6- = 6弱, 6+ = 6強, 7; this is not the Mercalli scale), maximum intensity per prefecture, and a detail_id for jma_get_earthquake. Use the filters to find significant quakes, e.g. min_intensity '4' or min_magnitude 5.

Full Japan Meteorological Agency (JMA) report for one earthquake: hypocenter (name, latitude/longitude, depth in km), JMA magnitude, JMA's tsunami assessment in Japanese and English (e.g. 'This earthquake poses no tsunami risk.'), and observed seismic intensity (震度) by prefecture → region → municipality, strongest first. Set include_stations to also get each seismometer's reading and coordinates (large quakes have hundreds). Identify the quake with detail_id from jma_list_earthquakes, or with its 14-digit event_id.

Tsunami warnings, advisories and forecasts (津波警報・注意報・予報) from the Japan Meteorological Agency (JMA). Returns the latest bulletin for each recent tsunami-related event, newest first, with: whether it is still in effect; its highest level (major_warning 大津波警報 > warning 津波警報 > advisory 津波注意報 > forecast 津波予報, i.e. slight sea-level change with no damage expected); coastal forecast areas grouped by category with expected maximum height in metres and first-wave arrival time (JST); observed tsunami heights if any; and the source earthquake (which may be far from Japan). any_warning_in_effect=false means no tsunami warning or advisory is active now.

Volcanic eruption warnings (噴火警報) from the Japan Meteorological Agency (JMA). Lists volcanoes in JMA's current eruption-warning feed with their Volcanic Alert Level 1–5 (噴火警戒レベル), JMA's status wording (e.g. レベル２（火口周辺規制） = Level 2, do not approach the crater; 周辺海域警戒 = stay clear of surrounding waters), whether the level was raised (引上げ) or lowered (引下げ), the affected municipalities, required actions and coordinates. Optional volcano filter by Japanese or romaji name (桜島, Sakurajima, 阿蘇, Aso) or JMA volcano code. A volcano that is not in the feed has no eruption warning in effect.