Tomorrow.io MCP App

The Tomorrow.io MCP App is a remote MCP server that shows interactive weather widgets right inside your AI assistant. Ask Claude about the forecast, air quality, pollen, or wildfire risk, and it answers with a live Tomorrow.io widget instead of plain text.

This page covers the MCP App connector. If you want raw weather data through the Tomorrow.io API with your own API key, see Tomorrow.io MCP.

Overview

• Server URL: https://api.tomorrow.io/v4/weather-intelligence/mcp
• Transport: Streamable HTTP (stateless, JSON responses)
• Authentication: None. You don't need a Tomorrow.io account or an API key.
• Access: Read-only. Every tool only reads weather data, and none of them creates, changes, or deletes anything.
• UI: Supports MCP Apps. In clients that support MCP Apps, results render as an interactive widget. Other clients receive a short text summary and structured data instead.

Connect

Claude (web and desktop)

From the connectors directory

1. In Claude, open Customize → Connectors.
2. Find Tomorrow.io and click Connect.
3. Start a new chat and ask: "What's the weather in New York this week?"

As a custom connector

1. Open Customize → Connectors → + Add → Add custom connector.
2. Enter the name Tomorrow.io and the URL https://api.tomorrow.io/v4/weather-intelligence/mcp.
3. Click Add. The connector needs no sign-in.

On Team and Enterprise plans, an Owner first adds the connector under Organization settings → Connectors. Members can then connect it themselves.

Claude Code

claude mcp add --transport http tomorrow-io https://api.tomorrow.io/v4/weather-intelligence/mcp

Run /mcp to confirm that the server is connected. Claude Code is a terminal client, so it receives the text and structured results without the interactive widgets.

Other MCP clients

Any client that supports remote MCP servers over Streamable HTTP can connect to the server URL. No headers or credentials are needed.

{
  "mcpServers": {
    "tomorrow-io": {
      "type": "http",
      "url": "https://api.tomorrow.io/v4/weather-intelligence/mcp"
    }
  }
}

Tools

All tools are read-only. Their annotations are readOnlyHint: true, destructiveHint: false, and idempotentHint: true.

Widget tools

Each of these tools renders an interactive Tomorrow.io widget.

Helper tool

Inputs

Each tool takes coordinates, not place names. Claude converts the place you mention (for example, "Paris") into coordinates before it calls the tool.

Single-location tools

Multi-location tools (show_current_6, show_aqi_6, show_fire)

What the tools return

Every widget tool returns three things:

1. Text content: a one-line summary for the model, such as Show Weather Forecast for New York City.

2. Structured content: the data the widget renders. Claude can also read it to answer follow-up questions.

   JSON

   {
     "widgetType": "weather",
     "units": "metric",
     "widgetData": [
       {
         "data": {
           "city": {
             "name": "New York City",
             "state": "New York",
             "country": "United States",
             "lat": 40.71427,
             "lng": -74.00597,
             "timezone": "America/New_York"
           },
           "daily": [
             {
               "timestep": "1d",
               "intervals": [
                 {
                   "startTime": "2026-10-14T10:00:00Z",
                   "values": {
                     "weatherCode": 1000,
                     "temperature": 17.8,
                     "temperatureMin": 12.59,
                     "temperatureMax": 19.52,
                     "precipitationProbability": 30
                   }
                 }
               ]
             }
           ]
         }
       }
     ]
   }

   widgetData contains one entry per location. The fields inside values depend on the widget. The air quality widgets include AQI and pollutant values, the pollen widget includes pollen indexes, and the fire widget includes the fire weather index and wind.

3. A UI resource: every widget tool points to ui://widgets/viewer.html (MIME type text/html;profile=mcp-app). MCP Apps clients load this resource in a sandboxed frame. It follows the host's light or dark theme and language, and shows a "Powered by Tomorrow.io" link.

Errors come back as a tool result with isError: true and a readable message:

• Could not fetch weather data for coordinates (lat, lng).
• Could not fetch weather data for enough locations (got N of M). A multi-location tool needs at least 2 locations that resolve.

Widgets

This is how each widget tool renders in an MCP Apps client. The screenshots use live data, in the light theme. Widgets also follow the host's dark theme.

Show Weather Forecast

tio_mcp_apps_show_upcoming. Example prompt: "What's the weather in New York this week?"

Show Weather Summary

tio_mcp_apps_show_summary. Example prompt: "Give me a quick weather summary for New York."

Show Multi-Location Weather

tio_mcp_apps_show_current_6. Example prompt: "Compare the weather in New York, London, and Tokyo."

Show Air Quality Index

tio_mcp_apps_show_aqi_mini. Example prompt: "What's the air quality in New York right now?"

Show Multi-Location Air Quality

tio_mcp_apps_show_aqi_6. Example prompt: "Compare air quality in New York, London, and Tokyo."

Show Pollen Forecast

tio_mcp_apps_show_aqi_pollen. Example prompt: "How bad is the pollen in New York today?"

Show Pollutant Breakdown

tio_mcp_apps_show_aqi_pollutant. Example prompt: "Break down the air pollutants in New York."

Show Fire Risk Index

tio_mcp_apps_show_fire. Example prompt: "What's the wildfire risk in Los Angeles, San Francisco, and Sacramento?"

Example prompts

Troubleshooting

The connector doesn't appear in my chat.
Open the + menu in the chat box, then Connectors, and check that Tomorrow.io is turned on for this conversation.

I get text but no widget.
Your client doesn't support MCP Apps (for example, Claude Code or some third-party clients). The data is still correct, and Claude can describe it to you.

"Could not fetch weather data for coordinates…"
The location couldn't be resolved, or the weather service didn't return data for it. Name a nearby city, or give the coordinates directly.

The widget is blank or doesn't load.
Start a new conversation and ask again. If the problem persists, disconnect and reconnect the connector under Customize → Connectors.

I hit a rate limit.
Wait a short time, then retry.

Privacy and data handling

• The connector receives only the tool arguments: coordinates and your unit preference. It can't access your conversation history, files, or account information.
• It doesn't require sign-in and doesn't collect personal account data.
• It uses the coordinates to look up the location name and weather data from Tomorrow.io's weather services.
• Data handling is governed by the Tomorrow.io Privacy Policy and Terms of Service.

Support

• Help center: support.tomorrow.io
• Contact: tomorrow.io/contact
• For API-key access to raw weather data, see Tomorrow.io MCP.