Open-Meteo MCP Server

GFS Forecast

gfs_forecast

Read-onlyIdempotent

Fetch US NOAA GFS weather forecasts by specifying latitude, longitude, and one GFS model. Returns hourly, daily, or current data.

Instructions

Get weather forecast from US NOAA GFS model. IMPORTANT: Specify exactly one GFS model in the models parameter (e.g., "ncep_gfs_global") — only one model per request is supported. For multi-model comparison, make one parallel tool call per model using the appropriate provider-specific tool.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`tilt`	No	Solar panel tilt in degrees (0 = flat, 90 = vertical); with `azimuth`, sets global_tilted_irradiance.
`daily`	No
`hourly`	No
`models`	No
`azimuth`	No	Solar panel azimuth in degrees (0 = south, -90 = east, 90 = west, ±180 = north); used with `tilt`.
`current`	No	Variables to return for the current time.
`end_date`	No	Date in YYYY-MM-DD format.
`end_hour`	No	Timestamp YYYY-MM-DDTHH:MM; hourly-precision alternative to start_date/end_date.
`latitude`	Yes
`timezone`	No	IANA time zone (e.g. "Europe/Paris"), or "auto" for the location's own. Default GMT.
`longitude`	Yes
`past_days`	No	Days before today to include, in addition to the forecast.
`past_hours`	No	Hours before now to include; alternative to `past_days`.
`start_date`	No	Date in YYYY-MM-DD format.
`start_hour`	No	Timestamp YYYY-MM-DDTHH:MM; hourly-precision alternative to start_date/end_date.
`timeformat`	No		iso8601
`minutely_15`	No	Variables to return at 15-minute resolution.
`forecast_days`	No	Days to forecast, starting today.
`cell_selection`	No	Grid cell to use near a coastline: prefer "land", prefer "sea", or the "nearest" cell.
`forecast_hours`	No	Hours to forecast; alternative to `forecast_days`.
`current_weather`	No	Legacy current-conditions summary; prefer `current`.
`wind_speed_unit`	No		kmh
`temperature_unit`	No		celsius
`precipitation_unit`	No		mm

Schema Changelog

Changes observed during successful MCP inspections.

Changed34 schema fields changedv2.5.0Sep 28, 2026

addedInput schema / $schema

Added value: +"http://json-schema.org/draft-07/schema#"

addedInput schema / additionalProperties
```
Added value: +false
```

addedInput schema / properties / azimuth

Added value: +{
+  "description": "Solar panel azimuth in degrees (0 = south, -90 = east, 90 = west, ±180 = north); used with `tilt`.",
+  "maximum": 180,
+  "minimum": -180,
+  "type": "number"
+}

addedInput schema / properties / cell_selection

Added value: +{
+  "description": "Grid cell to use near a coastline: prefer \"land\", prefer \"sea\", or the \"nearest\" cell.",
+  "enum": [
+    "land",
+    "sea",
+    "nearest"
+  ],
+  "type": "string"
+}

addedInput schema / properties / current

Added value: +{
+  "description": "Variables to return for the current time.",
+  "items": {
+    "anyOf": [
+      {
+        "enum": [
+          "temperature_2m",
+          "relative_humidity_2m",
+          "dewpoint_2m",
+          "dew_point_2m",
+          "apparent_temperature",
+          "precipitation_probability",
+          "precipitation",
+          "rain",
+          "showers",
+          "snowfall",
+          "snow_depth",
+          "weather_code",
+          "pressure_msl",
+          "surface_pressure",
+          "cloud_cover",
+          "cloud_cover_low",
+          "cloud_cover_mid",
+          "cloud_cover_high",
+          "visibility",
+          "evapotranspiration",
+          "et0_fao_evapotranspiration",
+          "vapour_pressure_deficit",
+          "wind_speed_10m",
+          "wind_speed_80m",
+          "wind_speed_120m",
+          "wind_speed_180m",
+          "wind_direction_10m",
+          "wind_direction_80m",
+          "wind_direction_120m",
+          "wind_direction_180m",
+          "wind_gusts_10m",
+          "temperature_80m",
+          "temperature_120m",
+          "temperature_180m",
+          "soil_temperature_0cm",
+          "soil_temperature_6cm",
+          "soil_temperature_18cm",
+          "soil_temperature_54cm",
+          "soil_moisture_0_to_1cm",
+          "soil_moisture_1_to_3cm",
+          "soil_moisture_3_to_9cm",
+          "soil_moisture_9_to_27cm",
+          "soil_moisture_27_to_81cm",
+          "uv_index",
+          "uv_index_clear_sky",
+          "is_day",
+          "sunshine_duration",
+          "wet_bulb_temperature_2m",
+          "total_column_integrated_water_vapour",
+          "cape",
+          "lifted_index",
+          "convective_inhibition",
+          "freezing_level_height",
+          "boundary_layer_height_pbl",
+          "shortwave_radiation",
+          "direct_radiation",
+          "diffuse_radiation",
+          "direct_normal_irradiance",
+          "global_tilted_irradiance",
+          "terrestrial_radiation",
+          "shortwave_radiation_instant",
+          "direct_radiation_instant",
+          "diffuse_radiation_instant",
+          "direct_normal_irradiance_instant",
+          "global_tilted_irradiance_instant",
+          "terrestrial_radiation_instant",
+          "wind_speed_200m",
+          "wind_direction_200m",
+          "snow_height",
+          "updraft",
+          "lightning_potential"
+        ],
+        "type": "string"
+      },
+      {
+        "description": "Pressure-level variable <variable>_<level>hPa, e.g. \"temperature_850hPa\".",
+        "pattern": "^(temperature|relative_humidity|cloud_cover|wind_speed|wind_direction|geopotential_height|vertical_velocity)_(30|50|70|100|150|200|250|300|400|500|600|700|800|850|900|925|950|975|1000)hPa$",
+        "type": "string"
+      }
+    ]
+  },
+  "type": "array"
+}

changedInput schema / properties / current_weather / description

Previous value: -"Include current weather conditions"New value: +"Legacy current-conditions summary; prefer `current`."

removedInput schema / properties / daily / description

Removed value: -"Daily weather variables to retrieve"

changedInput schema / properties / daily / items / enum

Previous value: -[
-  "temperature_2m_max",
-  "temperature_2m_min",
-  "apparent_temperature_max",
-  "apparent_temperature_min",
-  "precipitation_sum",
-  "weather_code",
-  "sunrise",
-  "sunset",
-  "wind_speed_10m_max",
-  "wind_gusts_10m_max",
-  "wind_direction_10m_dominant",
-  "shortwave_radiation_sum",
-  "uv_index_max"
-]New value: +[
+  "weather_code",
+  "temperature_2m_max",
+  "temperature_2m_min",
+  "apparent_temperature_max",
+  "apparent_temperature_min",
+  "sunrise",
+  "sunset",
+  "daylight_duration",
+  "sunshine_duration",
+  "uv_index_max",
+  "uv_index_clear_sky_max",
+  "rain_sum",
+  "showers_sum",
+  "snowfall_sum",
+  "precipitation_sum",
+  "precipitation_hours",
+  "precipitation_probability_max",
+  "wind_speed_10m_max",
+  "wind_gusts_10m_max",
+  "wind_direction_10m_dominant",
+  "shortwave_radiation_sum",
+  "et0_fao_evapotranspiration",
+  "temperature_2m_mean",
+  "apparent_temperature_mean",
+  "cape_mean",
+  "cape_max",
+  "cape_min",
+  "cloud_cover_mean",
+  "cloud_cover_max",
+  "cloud_cover_min",
+  "dewpoint_2m_mean",
+  "dewpoint_2m_max",
+  "dewpoint_2m_min",
+  "dew_point_2m_mean",
+  "dew_point_2m_max",
+  "dew_point_2m_min",
+  "et0_fao_evapotranspiration_sum",
+  "growing_degree_days_base_0_limit_50",
+  "leaf_wetness_probability_mean",
+  "leaf_wetness_probability_max",
+  "leaf_wetness_probability_min",
+  "precipitation_probability_mean",
+  "precipitation_probability_min",
+  "relative_humidity_2m_mean",
+  "relative_humidity_2m_max",
+  "relative_humidity_2m_min",
+  "snowfall_water_equivalent_sum",
+  "pressure_msl_mean",
+  "pressure_msl_max",
+  "pressure_msl_min",
+  "surface_pressure_mean",
+  "surface_pressure_max",
+  "surface_pressure_min",
+  "updraft_max",
+  "visibility_mean",
+  "visibility_max",
+  "visibility_min",
+  "wind_gusts_10m_mean",
+  "wind_gusts_10m_min",
+  "wind_speed_10m_mean",
+  "wind_speed_10m_min",
+  "wet_bulb_temperature_2m_mean",
+  "wet_bulb_temperature_2m_max",
+  "wet_bulb_temperature_2m_min",
+  "vapour_pressure_deficit_max"
+]

addedInput schema / properties / end_date

Added value: +{
+  "description": "Date in YYYY-MM-DD format.",
+  "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+  "type": "string"
+}

addedInput schema / properties / end_hour

Added value: +{
+  "description": "Timestamp YYYY-MM-DDTHH:MM; hourly-precision alternative to start_date/end_date.",
+  "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}$",
+  "type": "string"
+}

removedInput schema / properties / forecast_days / default
```
Removed value: -7
```

changedInput schema / properties / forecast_days / description

Previous value: -"Number of forecast days"New value: +"Days to forecast, starting today."

addedInput schema / properties / forecast_hours

Added value: +{
+  "description": "Hours to forecast; alternative to `forecast_days`.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

removedInput schema / properties / hourly / description

Removed value: -"Hourly weather variables to retrieve"

addedInput schema / properties / hourly / items / anyOf

Added value: +[
+  {
+    "enum": [
+      "temperature_2m",
+      "relative_humidity_2m",
+      "dewpoint_2m",
+      "dew_point_2m",
+      "apparent_temperature",
+      "precipitation_probability",
+      "precipitation",
+      "rain",
+      "showers",
+      "snowfall",
+      "snow_depth",
+      "weather_code",
+      "pressure_msl",
+      "surface_pressure",
+      "cloud_cover",
+      "cloud_cover_low",
+      "cloud_cover_mid",
+      "cloud_cover_high",
+      "visibility",
+      "evapotranspiration",
+      "et0_fao_evapotranspiration",
+      "vapour_pressure_deficit",
+      "wind_speed_10m",
+      "wind_speed_80m",
+      "wind_speed_120m",
+      "wind_speed_180m",
+      "wind_direction_10m",
+      "wind_direction_80m",
+      "wind_direction_120m",
+      "wind_direction_180m",
+      "wind_gusts_10m",
+      "temperature_80m",
+      "temperature_120m",
+      "temperature_180m",
+      "soil_temperature_0cm",
+      "soil_temperature_6cm",
+      "soil_temperature_18cm",
+      "soil_temperature_54cm",
+      "soil_moisture_0_to_1cm",
+      "soil_moisture_1_to_3cm",
+      "soil_moisture_3_to_9cm",
+      "soil_moisture_9_to_27cm",
+      "soil_moisture_27_to_81cm",
+      "uv_index",
+      "uv_index_clear_sky",
+      "is_day",
+      "sunshine_duration",
+      "wet_bulb_temperature_2m",
+      "total_column_integrated_water_vapour",
+      "cape",
+      "lifted_index",
+      "convective_inhibition",
+      "freezing_level_height",
+      "boundary_layer_height_pbl",
+      "shortwave_radiation",
+      "direct_radiation",
+      "diffuse_radiation",
+      "direct_normal_irradiance",
+      "global_tilted_irradiance",
+      "terrestrial_radiation",
+      "shortwave_radiation_instant",
+      "direct_radiation_instant",
+      "diffuse_radiation_instant",
+      "direct_normal_irradiance_instant",
+      "global_tilted_irradiance_instant",
+      "terrestrial_radiation_instant",
+      "wind_speed_200m",
+      "wind_direction_200m",
+      "snow_height",
+      "updraft",
+      "lightning_potential"
+    ],
+    "type": "string"
+  },
+  {
+    "description": "Pressure-level variable <variable>_<level>hPa, e.g. \"temperature_850hPa\".",
+    "pattern": "^(temperature|relative_humidity|cloud_cover|wind_speed|wind_direction|geopotential_height|vertical_velocity)_(30|50|70|100|150|200|250|300|400|500|600|700|800|850|900|925|950|975|1000)hPa$",
+    "type": "string"
+  }
+]

removedInput schema / properties / hourly / items / enum

Removed value: -[
-  "temperature_2m",
-  "relative_humidity_2m",
-  "dewpoint_2m",
-  "apparent_temperature",
-  "pressure_msl",
-  "surface_pressure",
-  "cloud_cover",
-  "wind_speed_10m",
-  "wind_direction_10m",
-  "wind_gusts_10m",
-  "shortwave_radiation",
-  "precipitation",
-  "rain",
-  "snowfall",
-  "precipitation_probability",
-  "weather_code",
-  "visibility",
-  "uv_index"
-]

removedInput schema / properties / hourly / items / type
```
Removed value: -"string"
```
removedInput schema / properties / latitude / description
```
Removed value: -"Latitude in WGS84 coordinate system"
```
removedInput schema / properties / longitude / description
```
Removed value: -"Longitude in WGS84 coordinate system"
```

addedInput schema / properties / minutely_15

Added value: +{
+  "description": "Variables to return at 15-minute resolution.",
+  "items": {
+    "enum": [
+      "temperature_2m",
+      "relative_humidity_2m",
+      "dew_point_2m",
+      "apparent_temperature",
+      "precipitation",
+      "rain",
+      "snowfall",
+      "snowfall_height",
+      "freezing_level_height",
+      "sunshine_duration",
+      "weather_code",
+      "wind_speed_10m",
+      "wind_speed_80m",
+      "wind_speed_100m",
+      "wind_direction_10m",
+      "wind_direction_80m",
+      "wind_direction_100m",
+      "wind_gusts_10m",
+      "visibility",
+      "cape",
+      "lightning_potential",
+      "is_day"
+    ],
+    "type": "string"
+  },
+  "type": "array"
+}

addedInput schema / properties / models

Added value: +{
+  "enum": [
+    "gfs_seamless",
+    "ncep_gfs_seamless",
+    "ncep_gfs_global",
+    "ncep_hrrr_conus",
+    "ncep_hrrr_conus_15min",
+    "ncep_nbm_conus",
+    "ncep_nam_conus",
+    "ncep_gfs_graphcast025",
+    "ncep_aigfs025",
+    "ncep_hgefs025_ensemble_mean",
+    "ncep_aigefs025_ensemble_mean"
+  ],
+  "type": "string"
+}

changedInput schema / properties / past_days / description

Previous value: -"Include past days data"New value: +"Days before today to include, in addition to the forecast."

removedInput schema / properties / past_days / enum
```
Removed value: -[
-  1,
-  2
-]
```
addedInput schema / properties / past_days / maximum
```
Added value: +92
```
addedInput schema / properties / past_days / minimum
```
Added value: +1
```

addedInput schema / properties / past_hours

Added value: +{
+  "description": "Hours before now to include; alternative to `past_days`.",
+  "maximum": 9007199254740991,
+  "minimum": 0,
+  "type": "integer"
+}

removedInput schema / properties / precipitation_unit / description
```
Removed value: -"Precipitation unit"
```

addedInput schema / properties / start_date

Added value: +{
+  "description": "Date in YYYY-MM-DD format.",
+  "pattern": "^\\d{4}-\\d{2}-\\d{2}$",
+  "type": "string"
+}

addedInput schema / properties / start_hour

Added value: +{
+  "description": "Timestamp YYYY-MM-DDTHH:MM; hourly-precision alternative to start_date/end_date.",
+  "pattern": "^\\d{4}-\\d{2}-\\d{2}T\\d{2}:\\d{2}$",
+  "type": "string"
+}

removedInput schema / properties / temperature_unit / description
```
Removed value: -"Temperature unit"
```

addedInput schema / properties / tilt

Added value: +{
+  "description": "Solar panel tilt in degrees (0 = flat, 90 = vertical); with `azimuth`, sets global_tilted_irradiance.",
+  "maximum": 90,
+  "minimum": 0,
+  "type": "number"
+}

addedInput schema / properties / timeformat

Added value: +{
+  "default": "iso8601",
+  "enum": [
+    "iso8601",
+    "unixtime"
+  ],
+  "type": "string"
+}

changedInput schema / properties / timezone / description

Previous value: -"Timezone for timestamps (e.g., Europe/Paris, America/New_York)"New value: +"IANA time zone (e.g. \"Europe/Paris\"), or \"auto\" for the location's own. Default GMT."

removedInput schema / properties / wind_speed_unit / description
```
Removed value: -"Wind speed unit"
```

First observedv1.1.3Jan 31, 2026

TDQS

A3.7/5.0

Behavior3/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint false, openWorldHint true), so the description need not restate them. It adds the one-model-per-request limitation, but says nothing about rate limits, data coverage/resolution, or availability caveats for GFS specifically. Adequate but not rich.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Two sentences, zero filler, with the most failure-prone constraint (one model per request) flagged up front. Nothing to trim.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 24-parameter tool with no output schema, the description covers only the model-selection pitfall and omits temporal parameters, units, and the 15-minute/hourly/daily distinctions. The schema descriptions carry most of that load, so it is minimally adequate rather than complete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

With 24 parameters and only 63% schema description coverage, the description must compensate, yet it only addresses the `models` parameter. That guidance is valuable (the enum mixes several non-GFS NCEP models), but the other undocumented parameters receive no added meaning. Baseline 3 for partial compensation.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource (get weather forecast) plus the exact data source (US NOAA GFS model), which clearly separates it from provider siblings like ecmwf_forecast or jma_forecast. It stops short of explicitly naming which sibling to use for other providers, so it is clear but not maximally differentiating.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives concrete usage guidance: pick exactly one model, and for multi-model comparison issue one parallel call per model via the provider-specific tool. That is actionable routing advice. It does not say when GFS is preferable to the other forecast tools, which is the remaining gap.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server

GFS Forecast

Instructions

Input Schema

Schema Changelog

TDQS

Other Tools