Fetch Weather Data via REST API

Use the REST API Call rule node to call the OpenWeatherMap API on a schedule and store outdoor temperature, humidity, and weather conditions as time series telemetry on the Building A asset.

Building A has a known geographic location.

ThingsBoard:

• reads the appid API key from the assigned customer’s server attributes
• reads latitude, longitude, and units from the asset’s server attributes
• calls the OpenWeatherMap current weather endpoint on a fixed interval
• extracts temperature and humidity from the response
• saves them as telemetry keys on the asset

In order to get weather data you should register on a website which will provide it. In this case OpenWeatherMap will be used.

After signing up there go to the API keys page to get your API key.

Open Customer A ⇾ Attributes tab and add a server attribute:

• Key: appid
• Type: String
• Value: your OpenWeatherMap API key

Go to Assets and create an asset:

• Name: Building A
• Asset profile: building

Open Building A ⇾ Attributes tab and add the following Server attributes:

Then, go to Customers ⇾ Customer A ⇾ Manage customer assets and click + Assign new asset. Select the Building A asset to assign to the customer, and click Assign.

You can import a ready-made rule chain or build it manually.

Option 1. Import rule chain

• Download the Outside Temperature/Humidity rule chain as a JSON file and import it into your instance.

Option 2. Create manually

• Create a new rule chain named Outside Temperature/Humidity, open it, and add the following nodes:

Add a Generator node connected to the Input node.

This node triggers a weather fetch on a fixed interval with the asset as the originator.

• Name: Trigger Weather Fetch
• Generation parameters:
  • Generated messages limit: 100
  • Generation frequency in seconds: 60 seconds
• Originator:
  • Originator type: Asset
  • Asset: Building A
• Generate function:

return { msg: {}, metadata: {}, msgType: 'POST_TELEMETRY_REQUEST' };

Add the Customer Attributes node and connect it to a Generator node with a relation type Success.

This node will put customer attribute APPID into the metadata of message.

• Name: Get Customer API Key
• Mapping of customer’s: Attributes
• Attributes mapping:
  • Source attribute key: appid
  • Target key: appid

Add an Originator Attributes node and connect it to the Customer Attributes node with relation type Success.

This node loads the building’s location attributes into message metadata.

• Name: Get Asset Attributes
• Server attributes: latitude, longitude, units

The values become available as ${ss_latitude}, ${ss_longitude}, ${ss_units} in the next node’s URL pattern.

Add a REST API Call node and connect it to the Originator Attributes node with relation type Success.

• Name: Fetch Weather Data
• Endpoint URL pattern:

https://api.openweathermap.org/data/2.5/weather?lat=${ss_latitude}&lon=${ss_longitude}&units=${ss_units}&appid=${appid}

• Request method: GET
• Credential type: Anonymous

On success (HTTP 2xx), the JSON response becomes the message body for the next node.

Add a Transformation Script node and connect it to the REST API Call node with relation type Success.

This node extracts the relevant weather fields from the API response.

• Name: Extract Weather Fields

var newMsg = {
  "outsideTemp": msg.main.temp,
  "outsideMaxTemp": msg.main.temp_max,
  "outsideMinTemp": msg.main.temp_min,
  "outsideHumidity": msg.main.humidity,
};

return {msg: newMsg, metadata: metadata, msgType: msgType};

var newMsg = {
  "outsideTemp": msg.main.temp,
  "outsideMaxTemp": msg.main.temp_max,
  "outsideMinTemp": msg.main.temp_min,
  "outsideHumidity": msg.main.humidity,
};

return {msg: newMsg, metadata: metadata, msgType: msgType};

Add a Save Time Series node and connect it to the Transformation Script node with relation type Success.

• Name: Save Weather Telemetry

• Trigger Weather Fetch ⇾ Success ⇾ Get Customer API Key
• Get Customer API Key ⇾ Success ⇾ Get Asset Attributes
• Get Asset Attributes ⇾ Success ⇾ Fetch Weather Data
• Fetch Weather Data ⇾ Success ⇾ Extract Weather Fields
• Extract Weather Fields ⇾ Success ⇾ Save Weather Telemetry

Save the rule chain.

Open Building A ⇾ Latest telemetry tab.

Within 60 seconds, the following keys should appear:

Download the pre-built dashboard as a JSON file and import it.

The Weather Dashboard displays Building A on the map, a table with humidity and temperature metrics, and real-time temperature and humidity graphs.

• REST API Call node — full node reference
• Originator Attributes node — how to load entity attributes into message metadata
• Rule Engine — ThingsBoard Rule Engine overview