Wunder2MQTT

Wunder2MQTT is a Home Assistant app that acts as a local HTTP bridge, translating Weather Underground (Wunderground) HTTP requests from weather stations into Home Assistant MQTT. Keep your weather data local by default, with optional forwarding to Weather Underground.

GitHub repository

Features

• 100% Local: No internet connection or cloud reliance required. Data goes straight from your station to your Home Assistant.
• Optional Weather Underground Uploads: Enable wunderground_forwarding to also upload each accepted observation using your station's incoming ID and station key. MQTT keeps working locally if cloud uploads fail.
• MQTT Auto-Discovery: Devices and sensors appear automatically in Home Assistant. Zero YAML configuration needed!
• Pre-configured (but extensible): The most common weather entities (Outdoor/Indoor Temp & Humidity, Wind, Rain, Barometer) are pre-configured by default. Does your station have extra sensors like soil moisture or solar radiation? You can easily add them via the app UI!
• Native Unit Conversion: The app forwards native metrics directly. Home Assistant handles all unit conversions (e.g., °F to °C, mph to km/h) based on your user profile automatically.
• Smart Timestamps: Incoming dateutc parameters are automatically formatted into standard ISO 8601 UTC timestamps, rendering perfectly in your local timezone.

Installation

Option A: One-Click Install

Click the button below to automatically add this repository to your Home Assistant:

1. Scroll down (or refresh), and look for Wunder2MQTT in the store.
2. Install, configure and start the app!

Option B: Manual Install

1. Open Home Assistant and navigate to Settings -> Apps.
2. Click the Install app button in the bottom right.
3. Click the three dots (menu) in the top right corner and select Repositories.
4. Paste https://github.com/csaboka21/Wunder2MQTT and click Add.
5. Close the dialog, scroll down (or refresh), and look for Wunder2MQTT in the store.
6. Install, configure and start the app!

Note: You must have a working MQTT Broker (like the official Mosquitto app) installed and configured in Home Assistant.

Configuration

The app comes with 11 basic sensors pre-configured (Temperature, Humidity, Wind, Rain, Pressure). If your station provides more data, you can easily add new sensors to the list. Enable "Log Raw Data" to see all incoming HTTP keys in the app logs, which makes it incredibly easy to find and map extra sensors!

Optional Weather Underground forwarding

Register a Personal Weather Station with Weather Underground and configure your console to send that station's ID as ID and its station key as PASSWORD to this app. Enable Forward to Weather Underground (wunderground_forwarding) in the app configuration. This shares observations with Weather Underground; the default is disabled. The optional local station_id / station_password settings only validate incoming requests and do not replace upload credentials.

Uploads use HTTPS RapidFire and preserve the original weather fields, independently of the configured Home Assistant sensors. RapidFire supports observations up to once every 2.5 seconds; configure your console accordingly. If you redirect station DNS, restrict that redirection to the station: this app must resolve rtupdate.wunderground.com to the real service. See the upload protocol and forwarding details.

Weather Station Setup

To route your weather station's data to this app, use one of the two methods below depending on your device's capabilities:

Method 1: App Configuration

If your station allows setting up a custom server:

1. Open your weather station's setup app.
2. Select Customized / Custom Server.
3. Protocol: Weather Underground (Wunderground)
4. Server IP / Hostname: The local IP of your Home Assistant.
5. Path: /weatherstation/updateweatherstation.php (or simply /)
6. Port: 80 (or whatever you mapped in the app settings).

Method 2: DNS Hijacking (For Hardcoded Stations)

Some weather stations (like the Raddy WF-100C) only ask for Wi-Fi credentials and hardcode the server to weatherstation.wunderground.com. To use these locally, you must intercept their traffic:

1. Provide a local Wi-Fi network for the station (e.g., using the Hass.io Access Point app with a USB Wi-Fi adapter).
2. Use a DNS server (like the Dnsmasq app or your router's DNS settings) to redirect weatherstation.wunderground.com to your Home Assistant's local IP address.

Troubleshooting

• Sensors aren't showing up? Check the app logs. Make sure it successfully connected to your MQTT broker.
• Seeing "Unauthorized" in logs? If you set a Station ID or Password in the app config, ensure it exactly matches what your weather station console is sending. If in doubt, leave them blank.