open-meteo-mcp-server

<div align="center"> <h1>@cyanheads/open-meteo-mcp-server</h1> <p><b>Geocode places, fetch global weather forecasts, historical climate, marine conditions, air quality, and terrain elevation via MCP. STDIO or Streamable HTTP.</b> <div>12 Tools</div> </p> </div> <div align="center">

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Public Hosted Server: https://open-meteo.caseyjhand.com/mcp

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Overview

Global weather from Open-Meteo: forecasts, history back to 1940, marine conditions, air quality, probabilistic ensembles, river discharge, and climate projections. Look up any place by name, pull hourly and daily variables, and run SQL over large results. No API key required.

Tools

| Tool | Description | |:---|:---| | openmeteo_search_locations | Resolve a place name to ranked coordinates with country, region, timezone, and population | | openmeteo_get_forecast | Current conditions and hourly/daily forecast up to 16 days, with up to 92 past days | | openmeteo_get_historical | Hourly/daily history from the reanalysis archive, 1940 to present | | openmeteo_get_marine | Wave, swell, and sea-surface conditions: up to 8 forecast days or an archive range | | openmeteo_get_air_quality | Modeled CAMS pollutants, pollen, and AQI: current, up to 7 forecast days, or an archive range | | openmeteo_get_elevation | Copernicus DEM terrain elevation for up to 100 coordinate pairs | | openmeteo_get_ensemble | Per-member ensemble forecast (up to 64 members, up to 35 days) for exceedance and uncertainty | | openmeteo_get_flood | GloFAS river discharge forecast (up to 210 days) or reanalysis from 1984 | | openmeteo_get_climate | Bias-corrected daily CMIP6 projections, 1950–2050, across up to 7 models | | openmeteo_dataframe_describe | List the tables and columns staged on a DataCanvas | | openmeteo_dataframe_query | Run a read-only SQL SELECT against staged tables | | openmeteo_dataframe_drop | Remove one staged table or view from a DataCanvas (opt-in) |

Capability reference

openmeteo_search_locations _tool

• A bare place name ("Paris", not "Paris, France"), with optional country (ISO 3166-1 alpha-2) and language (default en); count 1–10, default 5
• Each result carries coordinates, an IANA timezone, country / country_code, admin1 / admin2, population, and feature_code; no match fails as no_results
• A notice flags a top match with null or sub-100,000 population, which often means a historic exonym ("Bangalore", "Calcutta")
• A native-script query that misses under en is retried once in the language its script implies; effective_language names it when the retry succeeds (上海 → zh), and results come back localized

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openmeteo_get_forecast _tool

• At least one of current_variables, hourly_variables, or daily_variables (up to 50 each); forecast_days 1–16 (default 7), past_days 0–92 (default 0)
• Per-timestamp hourly / daily records with hourly_units / daily_units; current_variables adds a current object from 15-minute data (interval 900) plus current_units
• Prefer past_days over openmeteo_get_historical for the last ~5 days, where the archive's ERA5 components lag

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openmeteo_get_historical _tool

• start_date and end_date required (YYYY-MM-DD, from 1940-01-01), plus at least one of hourly_variables / daily_variables, named as on the forecast tool
• Omitting models reads Best Match (IFS HRES + ERA5 + ERA5-Land, source varies by date); up to 8 models pin a source. The ERA5 family runs ~5 days behind, ecmwf_ifs has no delay, and cerra covers Europe only
• Output echoes models and the returned date_range; with 2+ models each column carries a model-name suffix

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openmeteo_get_marine _tool

• One window per call: forecast_days 1–8 (upstream default 7) with past_days 0–92, or a start_date / end_date archive range back to at least 2022. Mixing them fails as forecast_window_conflict, a lone date as date_range_incomplete
• At least one of hourly_variables / daily_variables (wave height, period, and direction, swell, sea-surface temperature); sheltered water returns near-zero waves, a land point returns nulls (named in the notice), and ocean_current_velocity is null off the open ocean

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openmeteo_get_air_quality _tool

• One window per call: forecast_days 1–7 (upstream default 5) with past_days 0–92, or a start_date / end_date archive range from August 2022 (us_aqi starts a day later). Same forecast_window_conflict and date_range_incomplete rejections as the marine tool
• At least one of current_variables (a current object, interval 3600) or hourly_variables: PM2.5, PM10, NO2, SO2, O3, CO, dust, pollen, European and US AQI. Pollen is modeled for Europe only, in pollen season; elsewhere it comes back null and the notice names it
• data_source: "CAMS" marks every response as modeled grid data, not station measurements

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openmeteo_get_elevation _tool

• Parallel latitudes[] / longitudes[] arrays of up to 100 pairs; unequal lengths fail as coordinate_count_mismatch
• elevations[] in input order, each { latitude, longitude, elevation_m } from the Copernicus DEM (~90 m); elevation_m is null where the DEM has no value (latitude 90), without failing the rest of the call

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openmeteo_get_ensemble _tool

• At least one of hourly_variables / daily_variables; forecast_days 1–35 (default 7), past_days 0–92. Most models end within 16 days (ncep_gefs05 runs to about day 34); past that, columns are null and the notice says where data ends
• models takes one ensemble name (e.g. ecmwf_ifs025_ensemble, 51 members; gem_global_ensemble, 21); omitted or blank selects ecmwf_ifs025_ensemble, echoed in model
• Each variable returns per-member columns (temperature_2m_member01, …) across up to 64 members; member_count excludes the control run. A regional model queried outside its coverage fails as a non-retryable input error; switch to a global model

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openmeteo_get_flood _tool

• daily_variables required (up to 20), all in m³/s: river_discharge plus the statistics river_discharge_mean / _median / _min / _max / _p25 / _p75, which carry spread in forecast mode only (in reanalysis they repeat river_discharge)
• One mode per call: forecast_days 1–210, or a start_date / end_date reanalysis range from 1984-01-01. Mixing them fails as forecast_days_conflict, a lone date as date_range_incomplete
• Discharge comes from the largest modeled river within 5 km, not always the closest; vary the coordinate by ~0.1° when a value looks off. Null outside GloFAS coverage

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openmeteo_get_climate _tool

• start_date / end_date within 1950-01-01 to 2050-12-31 and daily_variables required (the API is daily-only); up to 7 CMIP6 models, e.g. CMCC_CM2_VHR4, MRI_AGCM3_2_S
• With 2+ models each variable is suffixed with the model name; a single or omitted model returns plain names. A variable a model doesn't carry comes back null

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openmeteo_dataframe_describe _tool

• Takes the canvas_id a spilled weather tool returned; lists each table's name, kind, row_count, and columns (name, type, nullability), plus the canvas expires_at
• Fails as canvas_not_enabled when canvas is off, or canvas_not_found when the ID is unknown or past its 24-hour sliding TTL

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openmeteo_dataframe_query _tool

• canvas_id plus a read-only SELECT against the staged table_name; rows holds up to 100 rows, fewer when wide rows would pass the 80,000-character inline ceiling (values are never cut). row_count is the exact total; page with OFFSET <rows.length> under an ORDER BY
• If the count fails or runs past 5 seconds, rows still return, row_count is a lower bound, and count_error names the reason (e.g. count_timeout)
• Fails as canvas_not_enabled, canvas_not_found, missing_table, system_catalog_access (system catalogs are blocked), or row_too_large (the first row alone exceeds the ceiling: select fewer columns, or shorten values with left(), substr(), or list_slice())

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openmeteo_dataframe_drop _tool

• Off by default: listed as disabled until OPENMETEO_DATAFRAME_DROP_ENABLED=true
• canvas_id plus the exact table_name from openmeteo_dataframe_describe; removes that one table or view and returns dropped and the remaining_tables. A name that is not staged returns dropped: false, so a repeated drop is safe
• Fails as canvas_not_enabled, canvas_not_found, or invalid_table_name (not a plain SQL identifier, or a reserved keyword)

Features

Built on @cyanheads/mcp-ts-core: stdio and Streamable HTTP transports, pluggable auth (none / jwt / oauth), swappable storage (in-memory, filesystem, Supabase, Cloudflare KV/R2/D1), structured logging with optional OpenTelemetry tracing.

Open-Meteo-specific:

• No API key for non-commercial use; commercial use requires Open-Meteo's paid API tier
• Columnar API responses reshaped into per-timestamp records with *_units maps, on the same variable names across forecast and archive
• DataCanvas spillover on the seven weather tools: with CANVAS_PROVIDER_TYPE=duckdb an over-budget result is staged as a DuckDB table (response carries canvas_id, table_name, truncated: true); with the default none it returns a bounded preview and truncated: true
• models on the historical, ensemble, and climate tools is not an allowlist, so a model Open-Meteo adds later works without a server update

Agent-friendly output:

• Location-first workflow: openmeteo_search_locations returns the IANA timezone alongside coordinates, ready for any weather tool's timezone input (default auto)
• Typed rejecti